My Meta AM29 has a pair of holes for the dropper, but i’m not convinced there’s an internal routing for it, just an empty space.

Is there a trick for getting the cable down the bike top-tube to the other hole ?

Gear cable inner threaded through the frame, then slide a gear cable outer over it (passing it through the frame), then connect the gear cable to the droppper hose and pull the hose through.

and how do i get it through ? is it just luck and waggling essentially or any other plans ?

I use a wire coat hanger straightened out then gently probe around until you get it through. I then push the hose end onto the wire and guide it through; you must ensure you maintain pressure pushing the hose into the coat hanger otherwise it’ll just pull off as you pull it through. In other words push from the hose end and gently pull from the coat hanger end.