The new channels.in feature in mIRC 7.69 bothers me.
I do use different [user].ini files with the command:
"C:\Program Files (x86)\mIRC\mirc.exe" -i"C:\[folder]\user.ini"

For different [user].ini files I preferred the old style channels to be in there, with the new feature I tried to specify another file / location in the [user].ini file, here:

[chanlist]
last=channels.txt

It keeps anyway using the channels.ini file in the C:\Users\[name]\AppData\Roaming\mIRC