Hello again.
To achieve yours solution, at least for a time being you will have to add configuration through CLI.
Open following filewith editor: vi /etc/config/mwan3
And add following configurations:
config policy 'only_mobile'
list use_member 'mob1s1a1_member_exclude'
config rule 'exception'
option src_ip '192.168.1.145'
option dest_ip '0.0.0.0/0'
option use_policy 'only_mobile'
config momber 'mob1s1a1_member_exclude'
option interface 'mob1s1a1'
option metric '0'
option weight '0'
And save it, it should redirect yours chosen IP (option src_ip '192.168.1.145' ) change IP in this line with the one you want.
Take notice of one more thing, if there is other rules with metric and weight set to 0 rise them up by 1, so the configuration you added would have highest priority with lowest number.
Best regards,
VidasKac.