In D13467#372676, @Brecht Van Lommel (brecht) wrote:

This patch adds functionality to work around limitations regarding editing properties of multiple objects for one specific case,
but really we need a more general solution for this. This would probably not be implemented in Python but in the core C/C++ implementation.

this "patch" (3 operators) is necessary, for enabling creation of UV atlas (combines uvmaps of different objects).
this may be important for many workflows .
this does not conflict or depend, on other multi-object features.
while, for T54862 to be implemented, it could take many months or years,
while these operators may actually stay the same, when needlessly implemented again.

if it would work -- it would not select concave and convex at the same time (when selecting "equal angle") . (as -90° (minus!) and +90° degree edges)