Yes, I once added two extra weeks of vacation time.

Yes. I was actually offered more vacation time because the company had to pay the recruiter a percentage of my first-year salary, but they didn't have to pay anything if they made increased PTO part of my compensation package. So, we ended up with the salary increase I asked for, with 3 weeks of it paid for by extra vacation.

I expect this is one where if you're coming from an Etsy or Google that gives 5 weeks after 5 years of tenure you could negotiate for preservation of that perk, but it seems like it could be challenging depending on your batna (see definition elsewhere in comments)