Well, r3dfox comes with SSUAO (site-specific-user-agent-override) support , so I bet you can set one just for chase.com and be done with (i.e., it won't affect other domains/sites) :
general.useragent.override.chase.com;"Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:128.0) Gecko/20100101 Firefox/128.0"
FWIW, "128.0" is the previous ESR version, currently at v128.13.0, which is supported for a month or two more , to be EoS'ed with v128.14.0; it's highly probable by that time that Chase's minimum requirements will get upped to "140.0" , the current ESR branch (now in v140.1.0) ...