I think the five fob ever thing only pertains to the new security update. Unless I’m mistaken you can program more than that unless you have the new update done. Now you have me wondering.
I went round & round thru all of this in 2018, well before any recent security update, when my widebody only arrived with one red fob.
( was a nationwide shortage at the time). The following applies to SRT Hellcat variants only:
Fob has to be OEM and New.
Once a fob has been married to a car (vin), it cannot be reused, so buying a "used red one" off ebay is not going to work. Repop are marginal - at best.
ALL Hellcat systems only allow up to 5 total fobs, then the system locks out any future attempts.
There may have been a work around exploit possible in the past to circumvent the total allotment on SRT hellcat models, (as other dodges can have up to 7, 10 & 12 more) but it was not something a dodge dealer could do.
The security update simply locked it all down to as it supposed to be, regardless of a previous used exploit to get additional fob married into the system beyond 5.