You can.But the prefilled one implies they’re already OK with the terms. Adding/changing stuff requires their approval. If both parties agree to the altered version, then there’s no problem.

I doubt they’ll allow a special case just for you, though.

I have returned additions/corrections to employment contracts and had them accepted. My usually go to is to change the overly broad “we own all IPRs developed by you” to “we own all IPRs that come from work related tasks or as a direct furtherance thereof”. If they want to own anything I developed outside work for my own projects then that’s fine, but then they’d have to pay extra.