16 June, 1969 New Vrindaban Letter to Arundhati
"Regarding your question about offering Prasadam, whatever is offered to the Deity actually it goes through the Spiritual Master. The Spiritual Master offers to Lord Caitanya, and Lord Caitanya offers it to Krishna. Then Radha Krishna eats, or Jagannatha eats, then Caitanya Mahaprabhu eats, then the Spiritual Master eats, and it becomes MahaprasadamSo when you offer something, you think like that and chant the Gayatri mantra, and then everything is complete. At last, ring the bell, take out the plate and wipe the place where the plate was kept." 
Iskcons system for offering bhoga-from their Deity worship website
Inviting the Lord to Take His Meal
In ascending order invite the deities to take Their meal. While doing this chant:
idam asanam and the mula-mantra for each deity.
While sitting on an asana and ringing a bell with your left hand, offer both padya (water for washing feet) and acamana (water for sipping) to your spiritual master and then to each deity, starting with Lord Caitanya and His associates and progressing to Krishna and His associates.

Prabhupada's system for offering arati
Letter to Himavati, Los Angeles, 1 April 1970
Regarding taking Lord Jagannatha to your next center, that will not be very good because you already do not have enough devotees to engage in Arcana. Unless there is a Deity worshipper available, we may worship Panca-tattva and Guru. That can be done by all initiated students whether they are once or twice initiated. Before an altar with pictures of Lord Caitanya, Pancatattva and Acaryas, everyone can offer Aratrik and Bhoga.
Yes, it is nice that you are worshiping Lord Caitanya along with Radha Krsna. That is alright. Lord Caitanya should be placed to the right side of Krsna. There is nothing special for His worship, but you may continue as you are doing now. The order of worshiping is first Spiritual Master, and then Lord Caitanya, then Radha Krsna (as in the mantras or Bunde aham prayer). Your confidence to do whatever you are instructed by the Spiritual Master is very encouraging. Yes, this is the method of the Vedic injunction, staunch faith in Spiritual Master and Krsna makes one perfect in spiritual understanding.
lecture, Srimad-Bhagavatam 6.1.10, Los Angeles, Jun 23, 1975
Therefore our first duty is to worship Caitanya Mahaprabhu. We keep the Deity. In the first we offer our obeisances to Caitanya Mahaprabhu along with His associate, and then, Guru-Gauranga, then we offer Radha-Krishna or Jagannatha.
lecture, Srimad-Bhagavatam 1.2.2, London, Aug 10, 1971
We begin from our first disciplic successionVande ‘ham sri-guroh sri-yuta-pada-kamalam sri-gurun vaishnavamsh cha. Vande ‘ham sri-guroh sri-yuta-pada-kamalam. “I offer my respectful obeisances unto the lotus feet of my guru, spiritual master.” Vande ‘ham sri-guroh sri-yuta-pada-kamalam sri-gurun vaishnavamsh chaAnd then, his guru, his guru, his guru, they’re all Vaishnavas. Vande ‘ham sri-guroh sri-yuta-pada-kamalam sri-gurun vaishnavamsh cha. Sri-rupamThen we offer respect to Sri Rupa Gosvami. Rupa Gosvami. Vande rupa-sanatanau raghu-yugau sri-jiva-gopalakau. All the Gosvamis, six Gosvamins. Vande rupa-sanatana… Sagraja. Sa agraja. Agraja means elder brother. Sanatana Gosvami was the elder brother of Rupa Gosvami, and Rupa Gosvami accepted him as his spiritual master. Sri-rupam sagrajatam saha-gana-raghunathanvitam. Associated by Raghunatha. There are two Raghunathas: Raghunatha dasa Gosvami and Raghunatha Bhatta Gosvami. Sa-jivam, with Jiva Gosvami. This is the processVande ‘ham sri-guroh sri-yuta-pada-kamalam sri-gurun vaishnavamsh cha sri-rupam sagrajatam saha-gana-raghunathanvitam tam sa-jivamThen we go to Chaitanya Mahaprabhu’s status: sadvaitam savadhutam. That is also…
 First of all, Advaita Gosañi, then Nityananda Mahaprabhu, Prabhu. Mahaprabhu is applicable only to Sri Chaitanya Mahaprabhu. Others, all prabhus. Ekale ishvara krishna ara saba bhritya [Chaitanya-charitamrita Adi 5.142]. Krishna, and He has got innumerable servants. Krishna is Mahaprabhu, and all others, they are prabhus. And the spiritual master who has got many prabhus to abide by his order, he is addressed as PrabhupadaThis is the system. So sadvaitam savadhutam parijana-sahitam krishna-chaitanya-devam. After offering all these obeisances to Gosvamis, to guru, and Advaita, Nityananda, then you come to Sri Chaitanya Mahaprabhu. Then Sri Radha. Not Krishna directlySri-radha-krishna-padan saha-gana-lalita-sri-vishakhanvitamsh cha. Radha-Krishna means they are always associated by thegopis, of whom Lalita-Vishakha are the chief out of the ashta-sakhis.

Iskcons system for offering Aratik

Offering Procedure for arotik
While standing on an asana and ringing a bell, present the incense first to your spiritual master by waving it in three or four graceful circles, and then present it to Srila Prabhupada and Lord Caitanya in the same manner.
Then, with the consciousness that you are offering it on behalf of your spiritual master and with the blessings of %Srila Prabhupada and Lord Caitanya, offer it with the full number of circles (listed below) to the main deity.
After offering the incense to the main deity, offer it as prasada to the Lord’s associates in descending order, and to the guru-param- para—senior to junior. This may be done with seven or three circles for each personality, depending on time allowance.

Some Conclusions—So in the two procedures of offering bhoga and Aratik- Iskcon differs (basically ) only in the way they offer aratik to the Deities. And as shown above this aratik procedure is incorrect and actually offensive to the guru param para and the Lord Himself.
If you accept their guru system (which we dont) then that is also incorrect, putting conditioned souls pictures on an altar filled with bona fide pure devotees which on that account of both systems of offering bhoga and aratik is wrong in Iskcon.
Why they do this?? Who knows why they do what they do anymore. I dont think even they know anymore there are so many contradictions they come up with.

Here is one answer from SB

SB 4.22.31-When one deviates from his original consciousness, he loses the capacity to remember his previous position or recognize his present one. When remembrance is lost, all knowledge acquired is based on a false foundation. When this occurs, learned scholars consider that the soul is lost.

Hare Krsna
Compiled by Damaghosa das

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