To stay within the sweet spot you need to continuously press and let go of spacebar, but this system is also interrupting by a skill check that also uses spacebar and if you mistime the press it can end your run. What this has lead to is that going to press spacebar to stay within the sweet spot can lead to an instant failure on a skill check with no warning. I seriously only see this combination of systems as they are now working together is if they each had a button tied to them rather than sharing the spacebar; there needs to be a warning before the skill check begins at the very least.