Can you remove the value for the configured schematics folder if it is using the default folder?
I'm using some git-repository setup to distribute my customized MC clients to my "users". I "develop" and configure the clients on my DEV machine and commit the configuration and changed mods etc. to the repository. These changes can be fetched / pulled automatically and saved to an arbitrary location on the target systems (like Desktop\LMc.1.7.10 or ~/LMc.1.7.10).
The pre-configured path for the schematics folder most likely won't make any sense on the target system, which is why saving an absolute path with a specific notation (e.g. Windows or Linux) in the config would cause problems.