MIMF

Gluing the bridge to the top?
Why not? It would make setup much easier for the players.

I would think because you would likely want to adjust it at some point.

What about a light pencil outline of where the bridge should go. I suppose one could use Elmers white glue and a layer of paper between the parts that would shear if you ever needed to move the bridge.

Here we have many centuries of fitting the bridge to the top without glue. The main concern is intonation and that changes with gauge of strings. You want to be able to move the bridge ever so slightly.
Don't mess with success!

The only good reason to glue down a bridge is because it's also a stop for the strings. Orville Gibson made them that way. Whether you glue it or not, the bridge has to fit that arch of the top , so it won't save any effort. If you're using a tailpiece there's no need to glue it down, and every reason not to.

I had not thought about different string gauges or intonation problems.
My necks are adjustable and resolves some issues with archtops.
My bridges are tightly fitted to the top and floating so far.
Currently if I or the owner of these guitars remove the strings and bridge I place tape on each side of the bridges with marks marking its placement.
However, this a process not required with a standard flattop guitar, and I’m sure this will lead to small intonation issues due to small variation in pencil marks with each change out.
Violin builder scrape the varnish under the bridge feet mostly for sound, although it could be used as a permanent marker.
Because I’m using a tail piece the bridge could be glued and adjusted for proper intonation before the glue dries.

If the intonation gets off at some date down the road there is lots of room to file the saddle to proper intonation, because of the height of this type of adjustable neck.
Just thoughts at this point

You seem to want to really try this out. So go ahead and let us know how it works out.

Your design is different enough that there might be a single optimal place for the bridge in terms of action adjustment and setup, and it might work really well for you. Certainly you already have a non-adjustable bridge for string height, which suits your neck design perfectly. On a normal archtop, every string gauge change and action adjustment, different brands of strings, indeed seasonal changes in humidity, makes you want to tweak the intonation. Once you adjust the bridge topper adequately you can do that with the movement of the base of the bridge. Equally as the guitar ages and the body move infinitesimally, the location of the bridge over the center of the instrument might change by 1/32" or 1/16", changing the string margins on the neck that tiny bit. These things are built into the nature of the instrument, and having a floating bridge on an archtop is considered by most a feature, not a drawback.

The greater height and smaller width on a typical archtop bridge leaves a greater chance that a bump in the wrong place would knock a glued bridge off, possibly tearing out some wood as it goes. From your picture, your bridge may have a bigger footprint, making it a bit less of a concern. Personally, I'd still worry about it though. Of course it's your call, but I don't find a floating bridge to be a problem really. They're pretty standard on Gibsons, Gretches and of course, banjos. If you do it, let us know how it works.

Thanks,
I guess for me this is a curiosity for options.
Perhaps on a future build with a shorter bridge.

Eldon Howe wrote:
"Violin builder scrape the varnish under the bridge feet mostly for sound, although it could be used as a permanent marker."

SOME violin makers do. Repairmen tend to hate them. Even a little bit of varnish goes a long way to toughening up the top surface. Once you scrape it off the wood wears very quickly. Pretty soon you have a dip in the top, usually oddly shaped due to the different hardness of the early wood and late wood. It's debatable whether wood to wood contact gives a better sound, but gaps in the fit certainly hurt it, and it's almost impossible to get a bridge to fit well once the top surface is worn like that.

I can see those issues Alan.
And my bridge did have a visible gap at each tip before the finish.
After the finish, had cured, I sanded the bridge to a proper fit and the volume did rise.