If it affects the wi-fi does that automatically mean it will affect the sound coming from your hi-fi system? They aren't the same thing.
Not saying it won't affect the sound but seems that without further evidence a conclusion is being jumped to.
Go to a show and you've got rooms with a poor sound and maybe a few with a good sound - but they are all using the same electricity supply. And how many SMPS will be operating in the typical hotel? I don't know but you've got to figure it's a lot. Yes, some demonstrators use regenerators but IME that doesn't seem to match up with who is getting a good sound and who isn't.
I've only got 2 things in the house using SMPS that are on all the time (in standby): the TV and the cable box. I can't detect any improvement if I unplug them while listening.
Current Lash Up:
TEAC VRDS 701T > Sony TAE1000ESD > Krell KSA50S > JM Labs Focal Electra 926.