This is more of a tool tip than a homemade tool.
If there is 1 thing that bothers me more than anything else is when having to turn entire OD of a part all the way up to the chuck when shucking up on the ID,
You always have to leave that last few thou. or risk crashing into the jaws. So what I do is use a large snap ring I have a few ranging up to 8" in dia I need some larger ones but haven't run across any lately.
Simply select the size closest to the ID of the cylinder you are turning place it over the jaws then it serves 2 functions 1 it is a spacer to reduce the risk of crashing while allowing you to turn the entire OD without having to remove and re-chuck the part from the opposite end depending on the part this may not always be convenient
2 in the case of a 4 jaw if you always loosen the 2 adjacent jaws at the gap in the snap ring you will always have the same setting or at least near to the same. That way if you have multiple parts to turn which have the same ID there is less fuss to get then trued before turning.
Another is the retracting action of the snap ring pulls the jaws inward so you don't have to loosen them off as much.
In my case I have a very old 4 jaw that I rarely use so it really helps to keep the jaws in the same position when opened.
These can be used on 3 jaw chucks as well and are a deterrent for them in-scrolling if the lathe is accidently started up without anything being chucked not to be relied on as the total prevention of flying jaws but they will offer at least some protection.
snap rings can be used for chucking on the OD of parts as well if you have some just slightly larger than the OD place one in the inner most grove of the jaws then clamp down on your part not much use for inside of a 3 jaw scrolling chuck but can be used as a part stop locator if one is careful and of no use for open chuck high speed in scrolling, but the snap rings will serve the same purpose for quick re chucking in the 4 jaws just follow the same procedure as chucking on the OD as you would for chucking on the ID