Amiga won't boot with ROMY installed, just black screen. The same with A3640 (rev.3.1). My friend had changed some e-mails with Cosmos, but one day Cosmos stopped to answer.
I have from Cosmos:
A4k Romy - working with custom KS3.9 1MB. Standard KS3.1 also working
PIO2 mod for A4000D - working
Exec.library for KS3.9 - working
And I have no problem with communication with Cosmos.
I don't know what kind of support you friend asked from Cosmos, but I know from my own experience that request like: "I have black screen, do something" cannot be answered.
I can look on that issue if you wish, but I need your Amiga.
Regards,
Stan