Comments:

Old versions (in my case 1.17.02.48, and a few other i cant remember) still say that 1.17.02.53 is the newest version

Saving .j2b's as mp3 does not quite work properly (although it didnt in 1.18.00.00 and i forgot to bring it up)
MPT incorrectly reads some songs endpoint, and therefore cuts the track early. This is most noticable (that ive seen, having converted near every j2b in existance) with dang.j2b and carrotus .j2b. Dangs original track length is 2:17 but is saved as 1:12, and Carrotus's original is 1:51 while saving at 1:22

(Can anyone else confirm the validity of this error, or is it local in my case?)

As for fixing support on custom .j2b's, the reading and quality is improved, but certain tracks still experience unexpected clipping.

Overall id give this a 9/10 and a definate dl recommend

EDIT
After some investigations it would appear that dang's length would be in the looping, (as mine is looped twice) and carrotus's would be in that for some reason mine has a 30 second outro that in not in the j2b for whatever reason, somehow a different version?

Still, a confimirrmation/ deny would be of interest to me.