First recordings of the Weigl 2nd and 4th Quartets have been out for a while, but the intonation of the Ensemble Mark Rothko makes these a chore to listen to. I'm familiar with 1st violin Carlo Lazari, who recorded the Rubinstein violin sonatas back in the 90s.
https://www.jpc.de/jpcng/classic/detail/-/art/werke-fuer-streichquartett/hnum/11522738 (https://www.jpc.de/jpcng/classic/detail/-/art/werke-fuer-streichquartett/hnum/11522738)
I also heard that recording and I concur with you. The 4th was somewhat passable, but the 2nd wasn't. A shame that this stuff is tackled by a flawed ensemble. Not sure if we'll have a proper performance/recording in the near future as these repertoire gaps have been "filled" already. Hopefully CPO will complete the cycle and also bring a recording of the 6th SQ.
2nd recordings of almost unknown works aren't unheard of, of course, and several of (maybe most of- even including the first of) Weigl's symphonies exist in duplication, but you're probably right- hope not though.
Hrm, it seems the last recording of his quartets that I'm aware of before this disc was the cpo recording of nos.7&8 back in 2019, but that did say volume 1. Hope cpo does indeed have more to come.