I think in most cases people will want to play the show, not transfer it. With MRS there is really no reason to transfer anything except in the case where you're trying to manage space. And if you need to transfer then you can explicitly go into the show description can select transfer. Pressing the play button on the remote should start playing the show via MRS, just as if it was on the local TiVo. It would make the whole experience much more seamless.
This is going to be even more of an inconvenience when the new streaming only box is released, since it wont have the option to transfer and playing via MRS will be the only option.
Hopefully this is just an oversight and TiVo will fix it in the next release.
Developer for VideoReDo