No Yamaha here, but I'll chime in that my (rear hub motor) bike's current controller (sent by the manufacturer last year to replace the original which died) can be configured & tuned via Bluetooth connectivity through a dedicated developers app. (The old controller, it seems, didn't have Bluetooth capabilities.) This isn't a feature the bike manufacture hints about in their sales materials at all, as far as I can tell -- I suspect they see it solely as one of their in-shop tools used during the initial assembly/build process, and not something they intended to ever be an end-user-accessible "tuning" app -- Having used the app now once, it is VERY easy to imagine seriously messing up key settings and introducing the potential for damage if you didn't know precisely what you were doing!
But the Level 1 Assist setting that was preconfigured by them, had been increased on this new one... Apparently after determining their customers generally wanted a bit more assist from Level 1 than my prior controller's configuration recipe provided. The new Level 1 felt like old Level 2 + a fraction. It was just WAY too much assist for me at Level 1 -- I had grown accustomed to riding almost exclusively in Level 1 to get more exercise out of my rides, and to go longer between charges by using less assist. They agreed to help me reset the configuration back to the "original" specs for all 5 Assist Levels, reverting to the percentage-output levels of my old controller. The Bluetooth connectivity enabled me to do that from home. I suspect for a controller without Bluetooth, I'd have had to send the controller back to the shop for them to retune it for me? Dunno...
That retuning took place after they directed me to the appropriate, obscure app to install on my phone, sent me a User ID & password to log in (into what exactly, I'm not really sure) -- at which point I could "see" my bike's controller in that app, connect to it in real time/live update mode, view an overwhelming number of data elements in a baffling number of nested menus, etc., and make the precise necessary Assist Level Power Output Percentage changes (with guidance from the bike crew on how to read and interpret just those things in the app -- it was not at all user-intuitive to me, and I'm grateful they walked me through it!)