That would be awesome. Much appreciated
I'd love to see what you can cook up with the T1 drivers. Since you're in Europe, you can probably get free samples of Twaron for damping: link
I'm certain that a T1 driver is noticeably smaller than a DT770s. Look at the driver against the baffle, there's a lot of baffle venting there.
(you can't really see the sloping from that angle though)
While I don't have extensive experiments or measurements to to back me up, to my ear it helped to cut down on a lot of the early treble reflections/peaks. Hard to say if it did much for the bass directly, though when you have an overall reduction in treble it makes the bass feel stronger.
The V-Modex has an airier sound signature which I think is due to the flat-ish treble response and possibly a decay ridge. Midbass on stock humps a bit, while here it sinks a bit then levels out. Bottom end reach I would say is on par with a T50rp with better pads, but the V-Modex has a bit more rumble.
Eh, I only had a brief listen with the LPs before I took them apart. They weren't bad, but nothing special to my ear. Heavy bass (but not overly so like some people say), not the best definition, kinda honky in the upper treble... that's all I can remember.
Hats off to you Nathan, amazing. Can't wait for you modding a COP T50rp if you ever get the chance. I would imagine you'd have a lot more room to work with a bigger cup and adjustable bass vents.