Well appears to be a glow plane since I see a fuel tank and a throttle servo/pushrod So yes I see that cut without any overlap would soon begin to appear nasty. This of course will depend on the exhaust flow pattern around the fuselage and where you have the exhaust outlet. Its impossible to know where that flow pattern is going to be until you fly it.
If you really want to do that then you will need to monocoat/ultracoat the edges to inside the fuse with overlap. Makes a whole bunch more sense to just use a Dubro switch/charge surface mount like most of us use.
John