Hi, I have problems with downloading the original split timer, so i want to use another one will my speedrun still be eligible?

yes a timer is a timer

You actually don’t even need a timer the mods will just retime

I think Doggo15 said it best, "a timer is a timer".

this sounds like that one kid in class when the teacher says "you may use a pencil and not a pen" and he says "well can i use a mechanical pencil?!" like yes of course you can use a different timer