Prof - we have demonstrated various improvement avenues for any / all Thiel models. Beetlemania posted his 2.4 results on this forum. There have been others. The upgrades all leave the basic stock platform unaltered, but upgrade various aspects that can benefit from improvement. I haven't done anything with the 2.7, since they are late-model and excellent. But, we know that we can improve them with our bag of tricks, if and when the time comes.
Regarding your stock 02s. I can recommend here a tweak that does no harm. Get inside and rig the fiberglass insulation away from the crossover network for better thermal management. Get some butyl rubber sticky-tape and route the driver wires away from each other (woofer / tweeter) and tape it to anything solid that you can, or just use the tape itself to keep it still. And, solidify the coils however you can. I add ordinary shellac or varnish and zip-tie them as tightly as possible.
Those coils were hand-wound, and their looseness robs transients.
These mild tweaks will tighten up the sound without changing the sonic character. Or, find another pair if you want to do more. First pass would be to move the crossover away from right behind and in line with the woofer EMF field. And then there's cabinet wall bracing and passive parts quality, etc. etc, etc.
