I got lucky. Some groups are super strict. I PM the recruiter and told him I cleared it as an i88 tank, but not as healer and I was only i74 (DL, allegen boots, relic weapon).

They let me in, I healed MT and we cleared T4 in one go. Was also my first time trying as healer.

Some will let you in.

But yeah, others will not budge. But if happen to have a character on Cerberus, I'll let you in.