Hey, welcome to the forum FBA! Good to have you with us.
You ask good questions, and I’m not qualified to answer. I have a question, if I may.
Are you seeking a classic “quad-view”, eventually? Something like…
Alternatively and “back in the olden days”, they (the modeller programmers/designers) sometimes used stuff like this… https://www.babylonjs-playground.com/#WWCK0#62 (run it a second time… to make dragging work)
I once made a simple “tri-view”… using BabylonJS viewports. (it’s actually a 5-viewport canvas, because the 2 blue divider-lines are also viewports).
If you ARE headed-towards 4-view (any of them can be told to go full-screen, of course)… then… hmm… maybe it would be best to think-about “custom viewport class” (a u-code-it extension of BJS viewport class).
4 sub-types/classes… ortho-left/right, front/back, top/bottom, and 3D. When any of the 4 types… is “focused”… THAT is when camera keypresses, camera mouse pans/drags, click/picks, and single/multi vertex drag/drop… turn “specialized”. All those things… get special “behaviors” for that type of viewport and mode. For vertex/vertices-dragging (and don’t forget snapping/quantizing - ahem), “selecting” is very important. Commercial modelling packages put heavy work into making their vert/edge selecting… powerful, as you likely know. FFD-box and space-warp ops, too. Beefy vert-wrangling stuff.
Custom behavior-izing 4 customized viewports… trying to make them portable and arrange-able on screen, and “focus-able” (to activate ITS behaviors)… I don’t know if that is the wise move, or not. It is just an idea, and it might be the direction that I would pursue… if I ever wanted to build a quad-view modeler in webGL.
Are we out-to make Blender’s and 3dMax’s quad-view/editor-panes… cry? hehe. Their quad-views are pretty nice. You could have a big task ahead… IF you wish-to make them ashamed to exist.
We could just blatantly STEAL the likely-Python quad-view from Blender… and… umm… nah, that won’t pay-off. hmm.
I sort-of complex-ified your basic questions, didn’t I? Sorry. I needed to know if you are going selecting and vert dragging in these views. Camera nav, keypress-nav, and vert-dragging… all sort-of need to stay in close-communication. I figged maybe… it was a wise time to ask “how big are we going, flybyair?” Sorry for so much yapping.
Stay tuned, surely LOTS better answers/ideas… coming soon.