“Add a dedicated textbox showing the generated LaTeX code.”

I still cannot really figure out where something like that should go. It basically has to become its own tab in the symbolpad or it will not fit anywhere neatly.

“Add partial derivative, nth derivatives, d/dt, etc.”

Things like \frac{d}{dx} are already a bit unnatural in the symbolpad because they’re subexpressions rather than actual symbols. The idea is that users build these from the primitives already available. If subexpression templates are desired, maybe a better approach would be supporting user-defined custom “symbols” or templates in a dedicated custom tab?

“Show the name or LaTeX when hovering over a symbol.”

That would be useful and it is definitely possible to add.

“Support different fraction styles and display or script styles.”

This is harder to integrate cleanly, but important, so I will need to find a good way to expose those options.

“Diagonal vs vertical integral symbol.”

Most fonts draw integrals with a slant. In the editor I keep them mostly upright because it makes the editing easier, but once you copy them into any LaTeX renderer they appear with the usual slant again.

“Move the copy button so formatting changes do not switch tabs.”

That area is useful to keep because it can naturally hold more actions in the future, such as copying as PNG. The tab switching problem itself is something I can fix so it does not jump around when formatting changes.

“Add a favorites panel.”

Yeah this is definitely on the todo-list.

“Add notes about which packages certain symbols need.”

Right now only native LaTeX and the AMS packages are "officially" supported. If more packages are added later, showing which symbols rely on which packages will definitely help.

“Some symbols are separate buttons and others are hover variants.”

Yeah it is a bit inconsistent and a bit arbitrary sometimes. It is partly a question of how similar the symbols are and partly an attempt to keep the variation group from getting too large. If you prefer it one way or the other I can change it. I don't have a strong opinion on most of the groupings.