I started gridding for get the 100% category but I notice that the only summited runs in this and the other categories are done in 2.0 baby version. I wanted to download this version to compete in the leaderboard but its not supported anymore and I can't find it anywhere. Is this version easier to run or does it have any difference that make it faster? If not, then why not just get riff off all version subcategories?

It's simply due to that being the latest version at the time those runs occured. That version isn't supported anymore and the runs are just there for historical value. The newest versions simply don't have as many people interested in running (except for One Badge, probably due to it being a short category). You can just run on the newest versions (which would be better to run given the updates since 2.0 Baby).

yeah but maybe want to run the old versions and the new versions since i speedrun every version of a PMD hack (well i used too,i kinda not been speedrunning as much as i as i used too) so maybe they want do same thing for main line game hacks like how some of spin off game hacks,like some versions of PMD sky hacks are faster and slower than each other. or some versions are harder then other versions or even have more content and updates. but then i don't speedrun this game but since i speedrun older versions of PMD sky rom hacks i wanted share what i think,so i understand if pokemon main line rom hacks are not handle like the pokemon mystery dungeon explorers of sky or first PMD rom hacks.