What you are describing is alternatives to a Tv priority mode.
Not really. I'm arguing that a straight Tv mode doesn't serve you very well, especially when the only other variable is ISO.
I agree. But straight Tv mode is something "standard" that photographers understand and expect. Can you imagine the howl if the next G17 or Canon/Nikon DSLR was released without it?
That's better than nothing, but it seems like what you really want is "use a fast shutter speed until the ISO gets really high" in the first case and "use the lowest ISO possible until the shutter speed gets down to 1/60th" in the second. This sounds a lot like "custom auto ISO", except that you'd want a more convenient and comprehensible UI.
Again, I agree and I'd take that mode too. Having updated the description of "custom auto ISO" for the manual and written the custom autoiso in kap_uav.lua, I think I under how it all works. But even I have to stare at it for a while to remember how it fits together. Having "OverExposure Compensation" in the same menu makes it worse of course.
In terms of making CHDK overrides adjust the unset parameters, if someone has a specific ISO set in the Canon menu and overrides the shutter, should CHDK mess with the ISO?
No, of course not. In that case, for most of the Canon P&S's, they are essentially trying to operate the camera in "M" mode.
I don't think we fundamentally disagree on anything other than this "needing" to be fixed. I can't think of a possible use case for setting one of Tv,Av,ND or Sv in the CHDK menus and letting the other three "float". Can you?
Meanwhile, we don't offer Tv, Av,Tv+Sv, or Sv priority modes. Or a good autoISO or usable ND filter management. While I don't disagree that an easy to use UI would be nice, that's not much of an excuse for not offering the modes at all.
Seems like we have games, and scripts for timing the cooking of eggs but not some of the standard stuff the more expensive cameras treat as normal. (Ok, cheap shot about the games, but I think you get my point.) And once you get started on the code, providing multiple shooting modes (M, Tv, Av, Tv+Av, autoISO, NDin/NDout) instead of just one is not a lot of extra work.