Ask HN: Compensating for uneven hours among founders?

Background: we're a small bootstrapped startup, with four founders with equal equity share. We're about half a year into the game, still feeding off of everyone's personal runway and paying no salary, but this is looking to change soon (which is brilliant!)

Due to differences in personal life situations, we are seeing that some of us voluntarily seem to be putting in more hours than others. Everyone is carrying their weight, so this is not a problem, but depending on a situation, individuals are finding themselves working through weekends, mainly due to their own volition and the fact that we're pretty thrilled about what we're doing. For some of us, facts of personal life simply do not allow this.

We've agreed on equal salary among the founders, but there's a growing suspicion that we should compensate for the uneven hours somehow, and we're exploring different options for that.

Does the HN community have positive/negative precedents on how to handle uneven hours among founders? An easy way out would be to start compensating for overtime in salary; however, this brings along issues like time tracking, which we're a little uneasy with.

Personally, I have been wondering if a more results-based approach would be more appropriate; after all, in these times I would encourage us to work smart rather than to work hard. Sales commissions (even among founders) could be one way.

Any thoughts? We're worried that if we somehow do not deal with this, it might lead to friction later. Any input is much appreciated.