@Szabolcs I tinkered a bit with my idea for a utility function IGEdgeSelect and came up with the following straight forward implementation:

    IGEdgeSelect[function_, property_][g_] :=
 With[{selection =
    EdgeList[
     g, _?(Function[edge,
        Not@function@PropertyValue[{g, edge}, property]])]},
  EdgeDelete[g, selection] ]

Usage example:

g = CompleteGraph[5,
  EdgeStyle -> {1 <-> 2 -> Green, 3 <-> 4 -> Green}]

I haven't tried all kinds of quirky edge cases but for my use case it works well and performance is fine

I am trying to reach @J. M. has anyone heard from him recently?

Folks first attempt here: community.wolfram.com/groups/-/m/t/1257547

Let me know if you have any design comments.

@user21 He's been missing for a while, but I do not know why. If you do not have his email address for direct contact, send me an email.

@Szabolcs, thanks. I have his email but I can not reach him. I thought perhaps someone here know anything.

Anyone here interested in publishing tools? I've developed a set-up that lets one go pretty much directly from a collection of notebooks to a GitBook and am wondering if it's worth writing a Q/A here about it.