I can't relate to stopping hrt and what effects that has, but I certainly empathize. I held off starting hrt in order to store specimen, which was just awful. Though in hindsight...if thats the worst I encounter in transition, I'd consider myself fortunate. But over the several weeks where I waited, with prescription ready, as I deposited...well, let's say I wasn't pleasant to live or work with. So I suppose my advice would be to keep focus on why you're holding off hrt: we have to make a sacrifice one way or the other, and sometimes the hardest ones will be necessary for the least regret. Keeping the option open to have a child is no small decision.
My advice for when the day comes you're ready to store: emphasize getting a consultation, regardless what the facility says is their policy. Despite going to a reputable cryobank in a very trans friendly environment, it took them until I was 2 months hurt (ie 2 months past my final deposit) to discover the full scope of what storing my specimen meant. No issues or potential danger in how my specimen have been treated or stored, but certainly a distressing headache that drag a up some super-dysphoric feelings, over a longer period than necessary.