First reaction, I wouldn’t consider it myself, not wanting to mess with the original plate. I would clean up that glue line though, that looks atrocious.
On the other hand, why not give it a try? Your luthier could attach the extension with hide glue (removable) and if it doesn’t work, just remove it.
I had a similar issue with a small bridge plate on an old D-18. The Trance is a good pickup, but I couldn’t make it work on that guitar, not enough room. I tried in front of the pins (on the saddle line) and behind the pins too. The plate was just wrong for the pickup, not seating properly, both positions way too trebly and not normal, so I gave up.
Since then though I’ve had great success on that plate with a PUTW 54 mounted in the flying V position on either side of the saddle line (narrow end of the V at the front). (This is the alternate PUTW mount position, the normal position being on the saddle line like the others.)
If I had known this at the time, I would have tried it with the Trance. I bet it would work well.
The PUTW is awesome in that position, so I’m a happy camper anyway.