I’m quite cautious about anything involving gamete donation out of concern for donor conceived people (while some are unbothered by their biological origins others are traumatised by it).
That said, it seems to me that this policy will help in making official, medically supervised donor conception viable for those who might otherwise have gone down the ‘private donor’ route, which can result in far too many children being born to one sperm donor and removes the rights of donor conceived people to access records relating to their conception and genetic medical history as well as the donors name in a controlled manner (after the child has reached the age of majority). These measures were introduced to support the long term wellbeing of donor conceived people (genealogy DNA websites mean there is no way to keep genetic parentage completely secret anymore anyway so it’s much better to have a supportive legal framework for DCP to find out about genetic relatives than leave them to muddle through after finding out by accident).
Clinic-based IUI also ensures the sperm used has been tested for STDs and some inheritable conditions, which obviously you don’t get if you buy a cup of sperm off some random bloke on a facebook group.
Plus it gives a same sex female couple a route to parental responsibility (including financial responsibility) for the non-pregnant partner that doesn’t involve the faff of the birth mother having to temporarily relinquish parental responsibility and adopt their own biological child as part of a couple, which is how it was 20 years ago (I was reference for some lesbian friends who had to do this almost 20 years ago. I had to do an in-person interview with social services! By the time their second child was born the law had changed and they could skip this faff. They are still together and their eldest just started university ❤️)
How anyone can ‘identify as a man’ and still want to carry a baby is somewhat beyond me but I suspect that the experience of pregnancy/maternity can contribute to detransition ideation and eventual detransition (it must be hard to keep convincing yourself that you are male when you are engaged in something uniquely female).
Again, NHS clinic based conception is going to be better for children of transmen than any alternative because the clinic can insist on withdrawal from exogenous testosterone and only carrying out IUI when hormone levels are back to normal female, which gives any resulting child the best chance of being full term and healthy.
Children (overall, not specifically DCP) raised by same sex parents seem to do well by all measurable means (education, employment, relationships, health) and women who are choosing single parenthood from conception are generally already sorted in terms of housing and economic security and have weighed up the pros and cons of doing it alone (as opposed to me who had an unplanned baby at 23 by someone I’d already broken up with before I wee’d on a stick 🙀)
So overall I think this is likely a positive development and the costs to the public purse are probably justifiable due to concerns about falling birth rates.