I’m assuming your curiosity is the early numbers were made here in US and later runs were sourced elsewhere?
(partly speculative but also based on information from Tom Thiel and my own SEs)
The 2.4SE debuted circa 2008. By this time, 2.4 crossovers were outsourced to China. An easy check is to pop out a passive radiator and look for Masonite point-to-point (Lexington built) or fiberglass printed circuit boards (China). Other than the SE prototype(s), it seems all SEs have Chinese crossovers with metalized polyester caps rather than polypropylene. Of course, the coax feed caps are those Clarity SAs which are the real deal (albeit surpassed by ESA, then CSA, and now Tom has announced an even further refined version).
Important to note that driver fabrication (and final assembly) for the SEs continued in Lexington. Jim Thiel, IMO, designed some of the very best drivers out there. Surpassed appreciably only by modern stuff like the Vandersteen carbon diaphragms and various “diamond” tweeters.