Thanks for the suggestions! I'll look into Mouseclicks, especially.
Yea, I can see it being an unusual request; I'm using FlyInside to run FSX:SE with my HTC Vive, and it's possible to bind a joystick/keyboard button to a "Show Mouse Cursor" action within FI. Someone at the FI forums posted an Autohotkey script that assigns mouse "left click" and "scroll wheel" to the hat, and it has worked great, but I was hoping I could run 1 less thing before firing up FSX. Not a big deal at all, though.
Practical result - don't have to take hand off the yoke and reach for invisible mouse, also trickier to aim with the mouse while using the HMD. Instead, just click a button on yoke and the mouse cursor pops up, look at button/dial you wish to interact with, then click a button on yoke to either scroll (heading bug, etc.), or flip a switch. It works really nicely, because for some reason when selecting items with head tracking like this, it's more accurate than with the mouse+head tracking. I think it's because you have 2 things you are aiming with when using the mouse (head tracking always moves cursor too), compared to 1 with just head tracking.
The dev for FI is most likely implementing the mouse left click action at some point, just figured I'd check here too.
Thanks again!