You'll have to be a bit more specific, while still being general, about the waiver in question. In other words, what does it pertain to? I can do some investigative work for you, but without some more information, I don't know where to begin.
Smokey
The quick and dirty.....
BFR expired is no problem. With a PPL, you can still log both PIC and DUAL received for your FAA logbook.
As for solo issue, we cover all those bases as well for your issue. We have a LOA with the Denver FSDO for these situations. A special endorsement will be attached to your training jacket, not into your log book, that will cover you to operate the DOSS aircraft in solo operations under the confines of the DOSS IFS operation only.
In other words, you'll be legal in the eyes of the FAA for what you do here only under the training syllabus you are enrolled in. It will not carry over in any other way to exercising your FAA certificate. And, NO, no IFS instructor will sign off your BFR under any circumstances. The BFR requirements are not satisfied by the training we provide you here. This training is meant to run you full throttle for 3 weeks and prepare you for UPT....
Cheers,
Smokey