If you have not been using the -m option, I suggest you do so.
https://gaiersoftware.com/Money/DetailsAndHelp The first time will generate
SymbolMap.csv into the current folder. If your
SymbolMap.csv does not contain the currency symbols, try adding these 46 lines to speed things and reduce traffic:
GBPARS,avy9p2
GBPAUD,avy9ur
GBPBOB,avyath
GBPBRL,avyau2
GBPCAD,avyb9c
GBPCHF,avyilh
GBPCLP,avybhw
GBPCNY,avybkr
GBPCOP,avybnm
GBPCZK,avyc2w
GBPDKK,avyc5r
GBPHHD,avyddm
GBPHUF,avydgh
GBPIDR,avydp2
GBPJPY,avyelh
GBPKRW,avyecw
GBPNZD,avygbh
GBPNOK,avygk2
GBPPEN,avyh27
GBPPHP,avyh52
GBPSEK,avyiim
GBPSGD,avyi4c
GBPTHB,avyiu2
GBPTWD,avyioc
GBPZAR,avyia2
GBPEUR,avycmw
GBPUSD,avyjhw
GBPGTQ,avyd27
GBPMAD,avyfw7
GBPTND,avyizr
GBPDZD,avy9m7
GBPILS,avydur
GBPMYR,avyff2
GBPBWP,avyar7
GBPKES,avyea2
GBPNAD,avyg5r
GBPBHD,avya4c
GBPJOD,avye4c
GBPTWD,avyefr
GBPOMR,avygmw
GBPPKR,avygpr
GBPQAR,avyhar
GBPSAR,avyhrw
GBPAED,avyjf2
GBPVND,avyjtc
GBPINR,avydm7
That does not address the ones that are not recognized. That could be a later thing to address. I understand this does not address your main points, but using the map can reduce the load on the server by not needing the look-up part.