I’m not so sure that suspending the scheduler is that important. It seems it is just an attempt to keep the block time correct, but it actually doesn’t do it, as the tick interrupt can still happen and increase the tick, causing the block to go too late.
What would be better would be for the “restricted” function to instead of taking a blocking time, a time to block too. That or make it a real critical section, and not just a scheduler suspension. And actually, having versions of the blocking operations that take a timestamp of the time to block to, rather than a time period could be useful for similar cases in user code.