Mike Abbott

ajz3d
Also, my another wish is that if C-Plane is enabled, viewport snapping (to front/left/up/bottom/right/back) respect C-Plane's orientation.

Agreed 100% on this - I believe I filed an RFE for this a few years ago...
The only single view that does respect CP orientation, as far as I know, is dropping down the 'Perpective' menu > 'Home' > 'Construction plane normal'.

ajz3d
The lack of "Align Handle" submenu in C-Plane context menu is a problem too. What's the point of a C-Plane if I can't align it with selected primitives?

You've got quite a flexible 'Align state' - semi-colon - that can be used with the CP.
But I do agree that Sidefx could make CP usage much better. It's an important tool in my book.

Well, perhaps the construction plane 'belongs' to the construction plane state : )
Personally I don't use the CP handle option available in the CP menu, I just toggle in / out of it with the forward slash key "/" - that puts you in construction plane state with the handle being active.

If it was permanently active it how would you, say move a point on an object if the construction plane was centred on that point?

Did you download the file attached to my post above?