I think you should just change 100 coins to 99 coins, just like stars, it would make it easier.
I mean you could set 1 coin for item ans still collect 100 coins, but i's harder to count for everyone. I'd suggest in this category to strictly match the "coins for item" with the number of coins you have to collect (10, 25, 50 and 99) so you can see on the screen the progress of the speedrun at each coins collected.
Louis just did this in their 10 coins grasslands speedrun... set 10 coins for item and went for the speedrun
I think these splits can be done by the runner, infotube probably added stars one on resources because i think he had one already and he wanted to help some ppl
Dont look at the image only, read the text. It was only there to illustrate what I wanted to say, we could in a single attempt, run for 10, 25, 50 and 99 coins simultaneously. We know you have to do the splits by ourselves