If the toe-in is correct @ 0 degrees you'll have no problems. You will have problems if you have 10 degrees or 15 degrees of toe-in. You'll hear lots of horror stories about this or that conversion but pay attention to all the little thing all will be O.K!! Make sure that your tailwheel is set-up properly & that it doesn't shimmy or shake.
While I might be able to agree with you on the handling vs the toe in/toe out situation, since the tubular gear has the axles made onto it, how do you adjust it? I do not know of any way to shim or adjust the gear legs.
Charles