Isolate curve as you do with object

Will not work . When you select key you also select channel it belong to (such behavor is not bad IMO). Some local mode could be the best option. It will let keep untouched visibility/locks options - isolate what needed > do whatever u need > go back.

When you select key you also select channel it belong to (such behavor is not bad IMO)

I don't see why, can you explain ?

If you could just select the channels to determine whch curves are displayed, it removes extra clicks. That is a quite significant improvement when in polishing stage.

So you "just select" channels to show only 3 chanels from 6 existent. Ok. Now you start working with keys - you select some key of some channel and selection jump to this channel... what should happen in this moment with your logic? Or you want to not synchronize key selection with channel selection?

I rephrase :
I don't see how this behavior is "not bad". What does it bring to the table ?

Because to me, I select a curve, not a channel, these are two distinct entities that should not be mixed as one.

Aha, now I get you. I think it is not bad option because I can do channel actions (like inserting keys or so) right from curves canvas without neccesity to move mouse to left panel (or with this panel hidden). Sometimes it is just some XYZ / RGB curves, so you know exactly which one is one you need - why move cursor left-right all the time.

I can't tell about others but I don't llike when software force me to select such things ONLY from some list. For example - I like in Photoshop to be able to select layer right from canvas by Ctrl+Click with Move tool.

The way I see it :

If you have either a chanel, key or curve selected, you should be able to mute/disable/hide channel, add or remove keys, so on.

That's how it works in most other animation softwares in my experience, and it is very handy. You have a huge flexibility with that. And that's when selecting channels to show/hide curves make sense : it is optional (linked to the "show only selected" option) and results in less clicking to obtain the same result.

As an animator I often spend time managing curves on several controllers; sometimes several dozens at once; If there is any way to save clicks and time; I'm for it. This IMHO is a great one Blender could use.
Let's say I'm polishing the rX of all my fingers, I can just select the fingers, search rotation X in the channel list; hit A to select all and that's it! Right now I would also need to press shift H to isolate them, then press alt h to get everything back to normal before re-isolating another selection, whereas I just need to change selection with the common behavior.