Certain infinite researches stop having benefits after certain levels - for example processing unit 13 gives you 100% recycling efficiency with modules, or railgun speed 2 is the limit because of a bug.

Would it be possible to have user configurable limits on techs so I don't have to catch when I reach a specified level and don't have to cross reference my current level

See here for more info https://www.reddit.com/r/factorio/comments/1h4v43o/infinite_research_magic_breakpoints/

This is nontrivial as I cant get this info programattically.

So I would need to hardcode that and then make sure to review it once every few months to make sure wube did not balancing changes.

Tbh, i went with WONTFIX. If you know these limits, just de-prioritize the research once "completed".