Hello.

Could you please add support for permission based support? Want to make that players can increase there shop limits by buying more using there votes. (So not for paid ranks/groups etc)

This may be able to be added at some point and perhaps someone will submit this as a pull request but unfortunately I don't have any time to work on non-essential updates right now.

Although you don't want to have paid ranks you could setup ranks that are hidden and separate from your actual ranks. Luckperms is good for this. You can set ranks with a different "weight" and on a different track so that the player never sees them. Then in Signshop config set them with their respective shop limits that you want then in your voting system sell those ranks as you would permissions. Just make sure that you add the rank to the player instead of replacing their current rank with it.
https://luckperms.net/wiki/Home

Hello.

Thank you for responding, and yea. Was planning to look into this. It would mean some "adjustments" in the current rank setup. But that is fine.