Prof - I think of you as I have worked on the 02. Somehow the 02 just sounds 'right' to you. I get it. I have a pair of unmodified 02s, and my living situation has a pair in which I have tightened up the hand-wound coils and replaced the off-the-shelf stranded hookup wire with Thiel solid / teflon, upgraded components to ERSE quality, as well as modified the grille frames for shallower angles. But fundamentally they are still 02s with second order slopes in dual-positive polarity with the tweeter signal arriving a cycle before the bass signal - like most speakers in the world. I believe that discontinuity allows the ear-brain to give the perceived signal a free pass, not subjecting the signal the rigorous reality check it gives a (first order) integrated, coherent signal. It sounds just fine, plus it's easy to listen to and doesn't draw attention to itself.
When developing the 02 research workhorse, I iterated various platforms and settled on first order slopes with the woofer on a stand-off and constrained listener ear-height . . . because that configuration allowed so much more obviousness between the variables I was comparing (wire, caps, resistors, layouts, wave-launch fluid dynamics, etc.) I used CS.5 drivers and crossovers with small modifications for the different cabinet. That product bears little sonic resemblance to the original 02 - its purpose is a modifiable, shipable, accessible research platform.
So if someone like you would want to upgrade your 02s, I would recommend upgrading the XO passive parts, moving the XO out of its present placement (in direct line of fire of the woofer electromagnetic field, and tweaking the grille frames while leaving the second order format in place. Within a few months (after I get the long-awaited ClarityCaps), I'll be firming up those mods to one of my 02 pairs. I'll post that saga here.
There is some low-hanging fruit on the CS2.7. There are big (up to 400uF) electrolytic caps including the midrange series feed, which break Jim's lifelong rule of paralleling any cap over 100uF. There is room in the cabinet bottom (excellent) XO location to add those caps. There are also polyester film caps where polypropylenes would upgrade performance. I would advise a CC or Purity in the tweeter feed. Big bang for buck improvement. Mills resistors could be sprinkled into the series feed stations. These comments reference an internet in-cabinet image which represents a down-grade of original as-designed 2.7s that I saw in the Thiel factory and show-samples. Individual evaluation would be necessary to learn what's in there.