"Add new items to shops": true,
"Name of the purchased product": "fluid.switch",
"The number of purchased goods at a time": 1,
"The purchased item is a blueprint": false,
"Number of payment items at a time": 30,

Blueprints would be very nice

New items from rust already get auto-added into the item list at the bottom of the config, just not directly into the shop categories anymore.
Because they would be default 1 for buy/sell which was an issue with players abuse buying before admins had a chance to update the shop config.  

I will add the blueprint feature update, however, there is no ideal way that everyone will be happy with.
The limiter feature is on hold still.

The latest update has added blueprint support. Please try it out and let me know, you cannot sell blueprints tho. Only buy.