pitfalls of using os timers with iyes_loopless fixed timestep?

[bcolloran]

I have a setup where I'm using the fixed timestep from iyes_loopless and, as expected, seeing jittering as renders happen on their own cadence that can differ from the timing of physics updates coming from the fixed timestep schedule. No problem there, I'm certainly comfortable rolling my own little buffer of values that will be need for interpolating the transforms data for the exact instant of the render, and comfortable writing my own timing logic.

My question is: the Bevy cheatbook warns strongly against using OS system timers (https://bevy-cheatbook.github.io/pitfalls/time.html) but if I'm already off the mainstream path and using fixed timesteps etc, does this wisdom apply?

I think I Know What I'm Doing (famous last words...), and I've read elsewhere that some of Bevy's timers are less useful if you're using a fixed timestep -- I think I fall in this category, but thought I'd ask for a quick sanity check since the cheatbook makes a strong recommendation on this point, and since I'm new to Bevy and gamedev in general.

Thanks all! Really loving using Bevy, and really appreciating this community!