Can I manually/programmatically put the battery charging on hold?
Here's a tool that I've seen recommended by others:
https://github.com/davidwernhart/AlDente
It can limit your charging to specific percentages. However, I've not used it myself.
Not really an already available solution, but Ezekiel put me on the right track: AlDente, while (currently; I've opened an issue) not working for me, attempt to writes a BCLM value in the SMC controller. So I've tried a different solution and found this one which does the job (from CLI).