as discussed here: https://www.reddit.com/r/kde/comments/jy7ms3/dolphin_sftp_does_not_work_if_ssh_hosts_config/

I am to the point that my ssh config has a LOT of hosts, so in an effort to make it more readable I went searching if there is a way to turn each host into a 1 liner, unfortunately there is no supported syntax for that, but I did find wildcards. For example you work for a company called Total Trance and have this config (notice how all the hosts in between the jump server and the wildcard definition do not have to list identity file, user, or proxyjump, this config works perfectly fine from the command line):

host jumptt
 hostname 111.222.333.444
 identityfile ~/.ssh/tt-home
 user citlalmino
 port 50123

host ttweb
 hostname 192.168.1.10

host ttemail
 hostname 192.168.1.11

host ttcloud
 hostname 192.168.1.12

host ttbackup
 hostname 192.168.1.13

host ttcalendar
 hostname 192.168.1.14

host ttdns
 hostname 192.168.1.15

host ttmysql
 hostname 192.168.1.16

host tt*
 identityfile ~/.ssh/tt-home
 user citlalmino
 proxyjump jumptt