Reporting data points. For research purpose.

P1 with Silver status:
P1 has two FFCs. During normal booking, one FFC does not show up.
Called in. Agent said let me convert the FFC into ETC.
Asked agent to convert the 2nd FFC into ETC. She complied. These two FFCs amount to about $150, ie. small value.

P2:
P2 has a bunch of FFCs. One FFC does not show up during normal booking,
Called in. Agent said that "They" have been very strict about converting to ETC.
She consulted helpdesk and got ok.
Converted all FFCs into ETC. Total about $1000.

Note: Some of P1 FFC may started with Travel Bank from P2. And vice versa.
Do not remember.
But some of the ETC of P1/P2 come to P2/P1 email address. That may explain why they were not showing up during booking.

P3:
Used Rebook into cheap fare trick, ending with two FFCs with the same PNR number.
Rebooking, one of them does not show up.
Called in. Agent decline to convert to ETC. But she did combine into one FFC.