Please update to 5.0.2 and let us know if it’s fixed there.

It would be like other blending modes, it would just automatically turn on Pigment mode in Paint / Wet Paint / Smudge tools. Now you have to do 2 things:
1. Change Layer blending mode to Pigment
2. Change tool mode from Standard to Pigment

After change you will have to only change layer blending mode

Yes it would make more sense for it to behave like other layer blending modes

There are 2 places to turn on pigment feature:
1. Pigment blending in Layers panel (not needed when you paint on opaque layer or you use a single layer for everything)
2. Pigment mode (or pigment blending) in Tool options

Bugs: i will be fixing them next week

Please write more details: brush you used, layer structure, layer blending, tool blending etc

one bug i found so far, looks like using "current and below" with pigment brushes makes the canvas flash

We are very proud to publish new beta with pigment blending. Please post your feedback in this thread! If anybody wants to joins beta tests please contact us be email: info@luckyclan.com.

How to use it:
- change layer blending mode from Normal to Pigment (not necessary)
- in tool settings change Color Mixing to Pigment (the other option is changing tool blending from Normal to Pigment)
- it works with any brush

Others:
- you can also use Pigment mixing in Gradient tool
- added Pigments color swatches group
- added Pigments brush group
- added Pigments gradients group

Yes

Will this be implemented in both the desktop and iPad version?

So we have some first results