i feel they should have a way to convert a mod from 2026.2 to older version

This is not possible because of how the software works. If you want older MC generators, use plugins for this.

If you change your mind and want to go back, the best way is to restore from a backup.

2024.4 does not have all features 2026.2 has so this is by definition not possible

Use 1.20.1 plugin on 2026.2

Sorry about the phrasing in reply to your comment on the 2026.2 article, I was a little annoyed and that was unfair. 
‎
I do want to state here the issues with this feature just to make it clear and help anyone who runs into this forum post:

• New versions of MCreator often introduce a bunch of features that older ones can’t understand and a ton of workspace files can all have references to a new feature. Workspace files also tend to reference each other a lot. This all means that it’s hard to remove all references to a feature from a workspace without breaking anything.
• MCreator is maintained by an incredibly small team (like 6 people do the majority of modern MCreator maintenance work), so they can’t afford to deal with people reporting bugs or having issues on older versions while also making new updates with cool new features. This means they can’t afford to do a backport tool or support people who use old versions instead of generator plugins. 
• If MCreator made a backport tool, they would have to deal with making back porting tools for every new feature, which is a lot of work. Also, how far would they have to go back? You wanted 2024.4 so they’d probably have to deal with supporting and testing every feature backported to 2026.1, 2025.3, 2025.2, 2025.1, and 2024.4 which is just too much work.
• Also, using an old version of MCreator is a worse experience than using a new one with a a generator plugin, so why would they put effort into old versions instead of just allowing plugins?

I personally recommend you move to 2026.1 and use _Spectrall’s NoeForge 1.20.4 generator, and make a copy of your workspace in 2026.2 to port it to 26.1.2. That way you’re forward-porting which they explicitly do support, instead of backporting which is unsafe and they don’t support.

Also, I realized that any removing features just removes stuff from your workspace so a backporting tool would a delete a bunch of stuff from your workspace anyways which is inherently an unsafe thing for MCreator to do and isn’t an ideal solution for anybody.