Settings files today are essentially a sim file without the bots (and without shapes and teleporters and so on). I think one of the original intents was to provide a meachanism for saving an 'empty sim' that could be used as a starting point over and over with different organisms. Perhaps also as a small size way to pass around settings and also to re-loaded the settings used at the last exist so settings are "sticky"
To be clear, it is currently *not* the set of settings (such as poff shots on/off, impact dots on/off, etc. ) that are sim independent. I will likely propose something on that issue separatly - this poll is about the utility (or lack there of) of user savable/loadable settigns files). But today, settings files are basically a sim file, but without the bots and other stuff.
Personally, when I want to start a new sim with the same settings as an existing one, I load the existing one and then "Start New". If I want different organisms, I delete the species and then start new and then add the new species. Basically, personally, I don't use settings files at all.
Most of what the default.set file has been used for in the past I.e. setting reasonable default settings, has recnetly gone internal to the code and future versions will likely do away with default.set independent of whatever is decided here (indeed, as of 2.42.9, a default.set is no longer necessary).
As above, the concept (though perhaps not the actual implementation) of a lastexit.set is worth keeping in that I think it makes total sense to re-load the program using the same settings that were used last time. So, independent of this decision, program settings will continue to be "sticky" across invocations, though I may do it with sim files or registry settings or something else instead. And yes, I know there are gaps with this today - settings that don't carry accross invocations becuase they are not put into the settings files at all. I will address this soon.
But personally, I think having user saveable/loadable settings files AND sim files is confusing, particularly since sim files can pretty much be used instead of settings files. I may be missing something, in which case I'd love to hear what, but I would like to do away with settings files in the code, in the UI, etc. It would be less confusing to new users and make the new self-contained setup code I'm working on easier (one less directory to create, etc.)