Is it possible to load channelstrips on existing track?
It is possible to make new track and use user template in configuration dropdown and then drag audio to new track.
I think there is much easier workaround for this, but I haven’t figured it out.

I use tracks live for multitrack recording and i would like to use ardour for all post processing and mixing.

Someone did begin a lua script that could be used to set an existing track/bus to a template, but only covered panning and fader values. It could be extended to cover other settings, but nobody has done this at this time.

So currently, using a track template when creating tracks and then dragging audio around is the only workflow I can think of that will do what you want.