"HW rulez" mod (add-on) for HoMM3.

Hotkeys are interesting; you just need to choose the most optimal and convenient ones for a specific action. You should test them out yourself before implementing them. Maybe it's possible to make them customizable?

That makes sense. I've already experimented with several of the features mentioned above, and I liked them. I think each player can express specific wishes here. Then, they can be summarized and implemented. I was thinking about customizable options. I'm not sure yet how to best implement them. The simplest option is a separate executable in the Heroes folder with a settings window.

By the way, does the HD mod have a hotkey for swapping troops between two heroes? And are there buttons to transfer troops back and forth between stacks? I know the rest.

I don't remember if those were available.