How Will the CSD/Headerbar Gnome Initiative Affect Fvwm?

Earlier today, from this Slashdot post, I became aware of the CSD Initiative, which, to my mind, is a needless “improvement” to the UI for the Linux desktop. When I see, listed as a goal, “No title bar”, well, my reaction is to say the least, less than positive.

I’m concerned, looking forward, what the impact will be for Fvwm as a Window Manager, and for Fvwm users. Will I need to become conversant with EWMH, and start including a bunch of Style statements in my config to ensure that GTK applications don’t disable the Title bar, and/or replace it with application widgets? Will Fvwm introduce a blanket config item which will enforce a system-wide ban on destructive changes to the window features, such as the Title area, and any other border/frame areas that the Gnome folks decide they need to mess with?

If this mess proceeds forward, will there be an issue with programs having widgets which will no longer display properly, unless the user/Window Manager allows intrusion into the window title area?

It’s not ideal, but GTK3 does allow modifications to the CSD titlebar -

I don’t use too many CSD apps, mostly just Chromium and Evince. But here is how I have dealt with CSDs, and it seems to be working so far.

Chromium still allows one to configure it to use the system window decors, and hopefully most apps will go this way, but the gtk3 apps are not doing that (or doing this in an easy, click a box in a config menu way).

Evince on the other hand took me a while to get right. My solution to evince was to only draw a border around the window, and then just use its decor. This fits my theme, I still get a nice fvwm border, I just don’t have duplicate of the buttons on my title bar and evince, though I do miss some of my additional buttons, I have a window list menu I can right click on the root window and do anything I need to the window. Here is my evince style line. I discovered turing off MWMDecor made it so fvwm could draw the decor, and I decided to remove the title.

Style Evince !MWMDecor, !Title

I am mostly concerned about The GIMP, and Sylpheed.

But will Fvwm, going forward, buy into this? I mean, will Fvwm allow replacement of the Title Bar with a CSD header?