H-1B holder serving as an unpaid startup advisor for equity only?

I'm trying to understand where the line is for H-1B holders when it comes to advisor roles.

A startup approached me about becoming an advisor. The role would be very lightweight, mostly occasional strategy discussions and introductions when helpful. There wouldn't be any salary or consulting fees, only advisor equity that vests over time.

I wouldn't be involved in day-to-day operations, have direct reports, or be expected to work a set number of hours.

Has anyone here been in a similar situation?

Specifically wondering:

• Is an advisor role like this generally considered permissible while on H-1B?
• Does receiving vesting equity (instead of cash compensation) change the analysis?
• Is the key factor whether the activities are considered "work" rather than how you're compensated?
• Did anyone have an immigration attorney review their advisor agreement before signing?

I know Reddit isn't legal advice, and I'll consult an immigration lawyer if I move forward. Just curious whether others have navigated something similar and what guidance they received.