Depending on the router manufacturer you may not be able to disable WPS pin and keep WPS push button (this is the case of the router that was supplied by my ISP as it comes with a rather dumbed down UI, not sure if I could disable it via editing a settings backup file and applying that back to the router as I use my own equipment, but most consumers will just use the router issued to them from their ISP). WPS enter pin has a max number of possibilities of 11k pins (it checks the pin in 2 half’s and the last digit is a check digit, so 10k possibilities for the first half and 999 possibilities for the 2nd half), and some routers don’t rate limit the connection requests.
Some router manufacturers fixed the issue by removing WPS pin, others “fixed” it by rate limiting WPS pin connection attempts, but that will just delay the attack.
So we are left with WPS Push button (if that’s available because as stated above, consumer routers may only allow disabling WPS completely rather than just disable WPS pin). But thats a bit of a pain for items like Shellys that are designed to be put behind fixtures.
But yeah, in the case of a fridge and most other consumer grade equipment putting a push button somewhere for WPS Push Button should be easy to factor in.