There is a known memory leak on the design tab. It’s less “leaky” now than when the issue was first reported a while ago, but it’s still there as of the last time I checked (within the past week).
How quickly the editor crashes depends on the “weight” of the pages being edited, the frequency with which different pages are visited, and the amount of “heap” memory available (which is a function of the amount of RAM on your machine).
I actually refresh the editor throughout the day; but I do what I call a “clean” refresh - i.e. copy the current editor URL, open a brand new browser tab, paste the URL into the fresh tab, and then close the “crippled” old tab. I have found this method of refreshing to be more robust than any other method - so much so that I added a hot key to my in-house Chrome extension so I can do it with a single key stroke.
Anyway, not much consolation I reckon, but that’s the scoop. Bubble is aware of it, but I guess it wouldn’t hurt to follow up with them and get the current status. 