As a Roblox developer, it is currently too hard to make or revisit old games that use R6 without publishing it, as due to a recent update you have to publish the place onto Roblox to be able to access the settings, and as a result if you haven’t set the place to R6 only or player choice, the option will be R15 only unless you publish the place.
If Roblox is able to address this issue, it would improve my development experience as I am more familiar with using R6, mainly because I mostly work on obby games, as R15 does not work well with obbies due to its different physics.