We rsync the jpgs (not the RAW files) to our self hosted photoprism instance. Not for the same reason you do, but it could easily be used the way you describe it!
Alternatively, if you don't shoot in jpeg+raw, or if you want to reduce the size of the jpegs before you sync them, digiKam has a batching tool that would let you automate exporting smaller versions of all of your files as part of the import process.