Change name again Q's - GRC etc

Looking at doing a second deed poll, many years after my first. My first deedpoll is dated 2018 and is a change of name from my birth name to a shortened gender neutral-ish nickname and a change of middle name to a gender neutral name. (Using fake names as an example)

Elizabeth Sophie > El Alex

This was due to a combination of factors - I identified as non-binary at the time, I was a teenager (16 almost 17) and it was sort of a compromise with my parents. Bla bla, many years have passed, I'm now on HRT and I've had top surgery and I mostly pass as male, but I have this kind of unusual name. I'm also an adult and have had loads and loads of issues with having a short name that looks like a nickname (lots of "have you filled in this form incorrectly?" Type letters and issues with getting on the electoral role, always needing to provide supporting ID etc etc), being misheard all the time or mistaken for a female name that's more common (think like "Mel", "Belle") and all around just being kind of a massive pain- it's sort of alright as a teenager but the issues have compounded over time and I'm now almost 25.

I'm now looking at doing a second deedpoll to basically have more normal traditionally male name, that my current name could still be a nickname for as to avoid more confusion than necessary - So something like El > Elliot. (Keeping the ambiguous middle name, since I don't think it's doing any harm.)

I also haven't updated any of my docs to have the right gender marker, I have Mx on my bank cards etc still, so the second deedpoll would also be a good chance to change a bunch of stuff to Mr and get my gender marker sorted.

Would this affect the "start date" for a GRC application, would they consider my second name change the start, even though I've already had top surgery etc...? I have evidence with Mx as a title and the odd thing with Mr (i.e. things I applied for more recently). It blurs the lines a bit I guess.

Also, because my first name change was as a minor, I didn't have many things I needed to change and it feels way more overwhelming to have to change so much stuff.

Any advice would be great thank you so much