It would be great if Telescopius remembered which telescopes have reducers and which do not. My astrophotgraphy scopes have reducers permanently mounted and the visual scopes do not. Currently you have to turn the reducer off and on (as appropriate) each time you switch telescopes.
…and the two astrophotography scopes have different reducer/flatteners. .7 and .8
So maybe what we need is a way to define entire telescope setups and select them with one click? That’s actually something I’ve been playing with but with a different approach: by being able to “add framings” to the current view, one could easily compare entire telescope setups, showing/hiding what you want.
This feature changes the entire interface of the current simulator. It’s a pretty big change but I’m halfway through it 
I know most don’t have that many telescopes, but I’ll bet that many have at least two. Thank you for the consideration. Unless I could see how your idea works, I’m not sure what I think of it. I thought mine would be simpler to implement, but maybe not. However, I look forward to seeing what you do, as I just added another telescope!