I finally managed to publish my first python scripts for krita. I’ve been using them for a while now and find them to be quite useful.
The extension consists of four actions that can be assigned to keyboard shortcuts:
1.Switch blending mode
One simple action that allows you to switch between mostly used brush blending modes.
If your most used brush blending modes are: normal, overlay, color
repetitively applying the action switches them like:
normal, overlay, color, normal, overlay…
It also allows you to go back from any other mode to normal one in just one click
2.Switch opacity
The same action, but for changing brush opacity instead of blending modes.
3.Set reference image
While doing a direct photostudy with a reference image opened in different krita document, it allows you to automatically set it to the same size, rotation and mirror value as your canvas. Helps keeping the proportions right when zoomed in.
4.Switch selection mask
No need to click the button to use local selection mask. This action switches between all the selection masks under current layer.
I also wrote a more detailed description of those actions, installation guide, and some troubleshooting guide if the things go wrong 
I hope it will work, and some of you will find it useful.
Any feedback from testing and usage are welcome.
Cheers 
Am using KanvasBuddy and the only thing left for painting was needing access to colour dodge; this has solved things. Working perfectly. 
blending modes is the only thing in a topbar that I can’t access any other way. Would love to have it in a RMB popup or brush tool options.
And, yes, I found that too, after looking through everything; with so many things being configurable it was a surprise to realise it wasn’t possible to tweak something. Then here your awesome script is!