Concerns about converting a BP with Infos to a BR with Infos are misplaced; on the one hand there are BR perms with infos and on the other the BP perm would continue to be a BP perm. Again, any issues relating to the use of Infos lie with the Perm not the EPE.
In practice it seems reasonable to expect that riders EPEing a BP would mostly validate by submitting a gpx track for the complete extended ride anyway, as that approach minimises the need to ride 'over distance' km to satisfy the EPE, and would in turn mean the validation process would follow the regular DIY path. These are procedural issues easily resolved. Where there's a will, there's a way.