It is OK to use a surge protector with 15 amp breaker on a 20 AMP circuit?
No, a surge protector is not rated as a PDU or subpanel.
Your concept does not work. You can't use a &quot;power strip&quot; with an onboard snap breaker as a substitute for a proper 15A circuit and breaker in the panel.  Not least, those 50 cent &quot;breakers&quot; are hokey-dokey compared to the real dual-mode things in your panel.
You can still do it, for other reasons
Given that you're doing everything with plug-in appliances and not doing anything with wiring in the walls, you are fine with doing that.  The WiFi switch (assuming it is UL listed; that's a big &quot;if&quot; for anything mail-order) only needs to be ready to handle normal current from the appliance.  UL has supervised its design and torture-tested it plugged into breakers as large as 20A.  UL has assured the design will not catch fire before the 20A breaker trips.
UL tests &quot;NEMA 5-15&quot; (15A socket) things to 20A, because an NEC rule is that 15A receptacles are allowed on 20A circuits, and UL itself requires that 15A receptacles be certified for a 20A pass-through.
This is the only case where NEC and UL allow mismatched breakers to sockets.  In all other cases, breaker, socket and load must exactly match.  (noting that 40A sockets are not a thing; therefore 40A circuits use 50A sockets).