If you wish to use Recurrent Complex as a utility and want it to only generate your custom structures, then you can disable all structures that come with RC by adding a simple rule to the config.

Open the config and use in file search (CTRL+F) to search for "structureGenerationMatcher." This option allows disabling certain structures or an entire mod's structures that uses RC's system, such as RC itself. Placing the following expression in this section will disable all default structures from generating: !$reccomplex. Your custom structures will still generate.

This option will still load the structures, which allows the user to use the edit command to view their rules in game, useful for referencing their rule set when learning how to use the mod. If you'd like to disable them completely and prevent them from registering (so that they don't clutter the command menu when searching through your own structures), you can instead put this expression under the "structureLoadMatcher" section.

If you want to disable most RC structures but keep a few that you like, you can make a list of the structure names and then after disabling all the RC structures, use the command /#map structureName ACTIVE. This will copy RC's internal structures to the active folder and enable them again. Note that to do this you must still have the default structure set loaded, so if you want to prevent the structures from cluttering the command list, you can add the expression above to "structureLoadMatcher" after you're done with the mappings. If the number of structures you want to keep is larger than the number you want to disable, it will be easier to just disable those individually (use comma separated list of structure names in the structure generation/ load matcher instead. E.g !AbandonedTower, !someNameHere, !etc).