So the universe is clearly angry at me for stealing too many photons last night and it's blessed me with clouds tonight. Fine, I needed to expand my dark library anyway. Here are some thoughts I had while doing that.

• If I have multiple cameras, I should be able to run the dark library tool in parallel for each of them, eg. guide camera and imaging camera.
• I'd like to keep the generated dark library someplace it can be shared (eg. a network drive) among various rigs. Yes, I've also got a dark library on my network share that I can use with Siril, but it's nice to let Ekos do some of that work for me.
• I'd like to be able to use bigger intervals. Right now it seems I can go up to 20s steps; once I get to a couple of 120s or 180s exposures I'd prefer to be able to increase by up to 60s for the generated dark sequences
• Dark library manager (DLM) limits me to collecting 20 darks for a given exposure range. Why not let me take as many as the sequencer would allow lights? This would probably help in compensating the bias too, right?
• DLM doesn't show me other capture parameters, eg. gain or offset.
• The CCD column isn't useful given that I already know what camera I'm operating on because of the drop-down
• DLM doesn't let me choose what gain(s) to use
• DLM doesn't let me multi-select and delete a bunch of darks that I didn't want
• DLM doesn't preserver sort order when deleting entries
• DLM can't sort by multiple columns, eg. first by duration and then by temperature

I maybe wrong but what you call DLM is for on-the-go dark correction of guiding cameras not for imaging cameras.
For imaging camera you collect darks the same way you collect lights (just select "darks" instead of "lights" - the software will remind you to cover the lens then.
Then you will be able to collect as many frames as you want at any exposure, temperature, gain or offset.

Yes, I already built a small dark library by running a series of dark sequences with my most common capture settings, then stacking them with siril... But this seems like something that could be automated even more. Putting button for the dark library on the CCD tab (not just the guide/solve tab) suggests to me that the automated dark library is intended for use with imaging too.

I am not sure about "DLM".
I built the dark library manually for my imaging camera (ASI2600MC).
I collected, saved and integrated:
90s, Gain 100, Bias 50 (a few frames)
120s, Gain 100, Bias 50 (a few frames)
240s, Gain 100, Bias 50 (a few frames)
360s, Gain 100, Bias 50 (a few frames)
etc.

I collected those a year ago and they still work fine.

Sure, I have a very similar library of calibration frames that I built with Siril and ASIStudio. I'm not saying it's hard to do, I'm saying it's a little bit tedious and I'd love it if Ekos could do this for me.