Bowden-direct hybrid
A Bowden tube is by design fairly small diameter to match the filament within, constraining the forces applied by the remote extruder mechanism. As you've noted, friction is a consideration.
For your application, you would not have to have such a tightly constrained diameter. You could use a Bowden tube for 2.85 mm filament, if your direct drive extruder is made for 1.75 mm filament.
You'd have the environmental control of the smaller tube, the path control and all of the other benefits, but none (or little) of the friction.
Additionally, you would not have the complexity of managing retraction or synchronizing feed that a dual motor system presents.