I bought something similar to this except mine came with a water nozzle and some tubing. This idea being that the staff would use it to slit concrete. They never used it, only an angle grinder.
I think the key is the blade not the power source.
Just make sure the glass in double glazed windows is of different thickness. Otherwise the inside pane vibrates in sympathy with the outside one.
Bathroom can be done . Simply that is has to be opened when showering and closed again. Or have a fixed pan and a vent fan.
And the point of this thread is?
That muffler is listed by Honda as an accessory. So you can request to have one fitted if YOU wish.
Also one can also buy dB killers for Yoshimura if YOU wish.