No way to see weight paint effect of a dynamic paint brush when tweaking it's settings

Thanks for fixing the weight paint not updating from dynamic paint objects in the viewport,

One issue though, you can only view weights in weight paint mode, but you can only see the weights of the selected object. This means if you have the brush selected to tweak it’s settings, there’s no way to see the effect that’s having on the weights of the canvas object (because it’s not selected).

Can we have a weights overlay for the main viewport, so we can see all the weights at the same time.

Something else too, it would be amazing if all of the modifiers that let you specify a weight group (such as displacement modifier), let you choose to invert the group. I’m sure this used to be there in 2.79, but seems to be gone now.