I don't know about HDR in Blender and the various ways you might use that. All I'm doing is correcting exposure of EXR in Blender since the image editor handles that and via nodes.
As for painting apps which I've digressed with on this thread. I found a regressive feature in the latest Gimp that for my purposes is very disappointing. Not that any other app can do this but that's why it was so cool in Gimp. Gimp handles MIDI which is Musical Instrument Digital Interface. It basically means you can hook a thing like this up and control everything with it's knobs and faders:
As you can imagine this is (was) superb.
Unfortunately the Gimp developers have changed the brush sizing feature, most likely in an attempt to make it easier to use but with that comes a major regression. It's a bit complicated to explain but the old Gimp had two layers of sizing. For example procedural brush sizes and bitmap brush sizes had their own size then this was scaled. It meant you'd make the bitmap size suitable for whatever you used it for in terms of scale. They have done away with scale and now the main size slider controls these underlying settings but it goes from 1 to 10,000 pixels. This is useless to try to set the size via MIDI. It's the main thing you want to dynamically change with MIDI. I can set my Wacom slider to do it but that just increments up or down slowly with little control. MIDI uses the new 1-10,000 pixel range across it's 0-127 range so has no sensible increments of sizing control. The Wacom, mouse etc is just crap compared to a MIDI knob or even a foot pedal.
Things like this make me go back to the real world. Software often regresses. Often it's the vision of one person and when that ends the software ends because it doesn't move forward and it has reliance on certain operating systems, hardware etc. In the real world simple tools can often last forever. I don't need to worry about whether my pencil is compatible with the paper or whether my guitar jack lead will no longer plug into my mixer. Computers and audio production are a total failure beyond simply recording audio tracks and editing them. This can of course be done in any old garbage app. Unfortunately 99% of them are garbage.