Since you are going electric the Supercoat isn't really necessary. Nitrate isn't proof against glow fuel and the Butyrate dope is at least fuel resistant. Even it needs raw fuel wiped off right away. I would suggest that for your project that you not worry about a glossy finish. WWI aircraft weren't particularly glossy to start with and the finish soon dulled out in the field. Mechanics would wipe them down to mop up the castor oil but they never got a wash and wax, so to speak. In our case the dope serves to adhere the covering, shrink it and to seal the grain of the silkspan. I don't know how much difference it makes on silkspan but on a fabric covered aircraft airflow through the weave of the cloth makes a significant difference. As to the strength of the fumes, everyone's perception is different but dope does use a significantly more volatile solvent. Relatively speaking it's like the difference between gasoline and diesel. One smells stronger but the other has way more vapor. On the up side you won't use nearly the quantity of dope to finish a triplane as you used stain and varnish to do a wooden door. It is certainly not as nasty as some of the catalyzed paints like Imron. Once you open the can you will get a feel for the strength of the fumes. Given that you have a good workspace and you have some experience with paints and solvents from work, I wouldn't fret over it too much. If you find the fumes to be troublesome get yourself a filtered paint mask.