We are just assuming you have a standard trans. You will need to find it to verify what size it is. I would leave as is, the power kit is needed when connected to a Chime, regardless of what type of transformer one has.
Here is another issue that pops up with the standard trans., you may experience random reboots, WiFi disconnects, loss of RTSP streaming. Not to say any of this will happen to you but just be aware if you have these issues, more than likely it is because the Doorbell is under powered.
Have you tried another App, to check Mech. Chime option? EZVIZ App sucks now that they took that option away after install. They also defaulted Mic On when receiving a Button Press Call.