Comment by Mister_Snuggles

Rather than regulating features, I'd start with a dependency list.

So a smart plug might have a list saying:

- Functionality requires 2.4GHz WiFi, Internet access, access to whatever.vendor.com, and a vendor.com account.

- Provisioning requires the above plus BLE and Vendor's app.

A smart washing machine might be more complex:

- Express wash requires nothing special.

- Regular wash requires 2.4GHz WiFi, Internet access, access to whatever.vendor.com, and a vendor.com account.

- Heavy Duty wash requires the above plus a vendor-supplied detergent cartridge.