Convertible notes/SAFE for Advisors?

The only problem with that is that some advisors are probably more productive than others and will provide greater value for less time. For true convertible notes, they should put up cash for the loan with terms and in the terms spell out the valuation triggers for equity so you don't give up too much.

https://www.strictlybusinesslawblog.com/2020/10/29/understanding-the-key-features-of-a-convertible-note-offering/#more-3560

With an advisor, you'll probably develop a regular cadence of meeting once every week, 2 weeks, month, etc. With a regular schedule, you should be able to estimate how many hours they're putting in, then convert that into an approximate percentage that seems fair. Whether it's 0.8% of 1.2% won't make much of a difference at this point in the company. And keeping track of hours for advisors could be a bit too much overhead, especially for someone with the experience an advisor probably brings to the table.

More importantly (to me at least) - the value of an advisor might not directly translate to hours worked like an engineer's would. Maybe they help with key introductions, which would be worth 100x the time it takes to make them. Maybe their presence on your "Team" page gives you instant credibility with potential customers.

A couple safeguards I had in place with a past advisor:

1. Have a few meetings first before a formal agreement is in place. There is value for both sides in making sure it's a good fit.
2. Establish a 1-year cliff and 2 or 4-year vesting period. If it's not working after a year, you can always get away with terminating the agreement and only giving up 0.25% or 0.5% of the company instead of 1%.