Acclimatization - needs to be addressed.
A East Coast SCR pilot can be assigned to a DHD at 12:00 into the SCR, DHD to London remain within the Table-B limits, receive 11:00 rest and fly the next FDP upto the full FDP limit in Table-B/C, while a Line pilot assigned to actually fly the two FDP's used to transport the first FCM, would need to apply the 0:30 penalty on the second FDP ... this is inconsistent and unrealistic ... who is more tired the line pilot on duty for 10:00 or the SCR on duty for 22:00?

Rescheduled FDP start time also needs to be addressed.
Technically, not even in the reg, it is just because of interpretation by the FAA, just write the regulation. The FAA could learn from the EASA FTL regs on this subject.

Disruptive Schedules (Day to Night and visa versa)- was partially in the original NPRM of the reg for SCR. FAA could learn from EASA and CASA on this topic.

117.23 - Cumulative FTL & FDP , again language does not support the FAA's interpretation (which I think is correct), so a loophole can be found and brought to suit in court. They can close it up by changing the language to:
No certificate holder may schedule and no flightcrew member may accept an assignment or continue an assigned flight duty period