Curious - do you have hardware acceleration disabled? Rotating the scene shouldn't be hammering the CPU if hardware acceleration is enabled. [disclaimer: I work at Desmos]
Looks like 117 was just broken
For example, variable X is continuously cycling between -10 and +10, but only when variable D is > 1. At my son's school, there is a kind of interactive demoscene going on using Desmos (the kids believe that the school cannot block Desmos from the Chromebooks, therefore they will always have it available).
(1) the more straightforward (but less powerful) option is to use the dynamic bounds for a slider. Here, "a" is set to animate, but the bounds don't let it move if b=0: https://www.desmos.com/calculator/mqhhpso67r
(2) the more general feature that allows for complex scripting behavior is called "actions." Here's an example that uses that, where it's more of a genuine play/pause: https://www.desmos.com/calculator/gzqwx36lo0
It's a beta feature that needs to be enabled, but anyone can turn it on. More here: https://help.desmos.com/hc/en-us/articles/4407725009165-Acti...