Thank you for considering many of my suggestions and keeping a to-do list for the features that haven’t been implemented. 
Samplers, windowing and docking
The current problem that I have with it is that its real estate is quite small and not vertically adjustable. Please make it so. I also tried turning on the floating dialogue setting but there is no way to make samplers a window. Maybe make it like GIMP or Inkscape where the user could dock or detach everything at will, including histogram, samplers and even the layers dialog.
More sampler features to consider
1 I don’t know if you followed GIMP Guides and Sample Points but @prokoudine’s mock up is fairly robust. With a little refinement, samplers might be my favourite tool yet.
2 Like with WB, I hope to have an option to use an area sampler.
3 Unsure whether I mentioned this before, but I would like the option to delete a sampler. I don’t like having to drag it to a new location. I would rather delete it and plop it down somewhere else.
4 Along those lines, it would be rad if I could (re)name these samplers. I don’t think this is a feature in any app. A labelled sampler could also double as a general label to remind me of something when I open an old or incomplete pfi.
Edit: 5 Previously, I mentioned being able to switch between various RGB and R’G’B’. What I meant was being able to change the values to reflect RGB other than the working profile’s. E.g., if I use Linear Rec.2020, it would be super useful if I could view the coordinates in standard sRGB, etc.
PS Floating dialogues feedback
1 First time I switched over, I didn’t know how to activate the window. Apparently, at least on Windows, I have to double click the tool layer in question. I would rather it be a single click.
2 Another thing is the [x] of the windows are faded out, at least on Windows. The only way to dismiss each is to press [Esc].
Opening 2nd, 3rd, etc. raw sometimes crashes PhotoFlow. Don’t know how to make more predictable. This is not a new problem; I reported this before.