Your right. A Linux send only node cannot receive changes. However a Linux send only node could temporarily (then send only could be turned on) be used when all nodes are online to change file/ folder case(s) on Windows nodes. A two step rename could do the same thing with all nodes online too though. All a send only node really does is allow a case change without all nodes being online at the same time at the expense of not being able to add files to any other node until all nodes do come online again.
Despite how convoluted that is still cannot think of a better solution to change case. If Syncthing implemented a system to check if folders with different case are the same how would that effect case sensitive file systems where users want two identical folders with the same name in different cases? Granted that likely rarely occurs but any such case change system may have unintended consequences on case sensitive operating systems. Completely agree (almost) no one is going to do this but believe a solution to any problem uniformly handles any variable of a given situation. Still it would be neat if someone could figure it out.
My guess is that there is a 1:1 relationship between files and that on Windows Syncthing uses the initial case for a file/ folder.
Believe file “memory” consists solely of deleted files to prevent from being brought back from a long offline node as it was explained to me. Fairly certain versioning just moves files to the .stversions folder instead of removing and lacks any “memory” about what it is doing.
If we could come up with a specific and realistic suggestion on how to implement seamless case changes feel like it would be seriously considered, written, and likely implemented if it was possible.
Do you have other ideas on how case changes on Windows could be implemented that also addresses case sensitive file systems being able to have identical folders with different cases?