OnePlus15 and OOS16 customisation

Well, after waiting faithfully for some significant upgrades on the Samsung S26, and being kinda disappointed, the OnePlus 15 came to my attention.

It seems amazing, the insane battery life, display and unreal performance. The only thing keeping me from ordering one this instant is the potential for customisation on OOS16. I love tinkering and personalising my experience and that is the main thing I was looking forward to on OneUI. Is the software on this phone customisable, at least more than iOS (which I am coming from)?

Thanks :)