It should be noted that Ireland's self-ID law has an exception for prisons. No male can ever be sent to a female prison.
In terms of the UK - even if we ignore safety for women and girls, the female prison estate is tiny (circa 5-6k capacity) with barely any provision for dangerous prisoners as there are so few dangerous female prisoners. We couldn't even accommodate a large batch of TIMs.
I think, at the absolute bare minimum, nobody already convicted of MVAWG or sex offences should be eligible for a GRC. And GRCs should be withdrawn if a holder subsequently commits such offences. Male pattern offending has no place in women's prisons. And male pattern offenders have no place in women's spaces outsdie prisons.
I have seen suggested elsewhere that the GRC process should include a comprehensive psychological risk assessment. Applicants should be assessed for their understanding of boundaries, consent and other red flags that indicate a propensity for male pattern offending. GRC applications should be declined if the person cannot perceive of women as full human beings with rights to boundaries and consent.
"Genuine" transitioners should have nothing to fear from such a process and, indeed, their own safety post-transition would be enhanced by it.