But, for example, if next update will include updates to both DB fields and references in code, we may solve the problem.
As far as I know you changed also ptahs e.g. for satistics. This will mess up everything on update.
The only otion that I see at the moment for an inclusion is to rewrite your addons so that it follows the ispconfig paths and databse field names.
I'am sorry but I really can not include a piece of software even in a next major release that will break thousands of exsiting server installations.
Nevertehless I will review your code and see If it can be made compatible with the released ispconfig versions as it will be less work to chnage your plugin then to cahnge the whole ispconfig code to make it compatible with your plugin.