I've done some machine tieing on smaller quilts, works great. You will still have to wrestle the quilt through the harp though. One caveat, the same spacing rules apply as they do in machine quilting, perhaps even more importantly.
Wash and wear on quilts that are tied creates a lot of shift and pull on the tied areas.
I'd make them no further than 4" apart.
All good ideas here, and happy new stash!