The potential problems with fast scopes are two fold.
Firstly, (including a diagonal) most binoviewers require 145-200 mm of inward focuser travel to reach focus. This can be mitigated by installing a Barlow but this comes at the expense of the available field. .
Secondly, the fast optical cone is vignetted by the entrance pupil of the binoviewer which can constrain the available field.
Your options on fast scope are to either use one of the zero-optical-length binoviewers or install a Barlow. The former typically has a 17mm entrance pupil. With the TV101, this translates to a maximum field of 1.8°. If you go the route of the MB2, you will certainly need a Barlow and your visible field is unlikely to increase meaningfully. Be cautious that a prism is a poor choice for a diagonal at f/5.4. This means that even a relatively short set like the Mk V or MB2 are going to need about 160 mm of focus travel. I don't think the NP101is has this much focus travel available (I found 129mm) so you're almost certainly going to need the 1.7x Glass Path Corrector
This is almost as good as it gets - I specified a 115mm f/7 scope specifically for binoviewing and can achieve a true field of 2.0°. (In practice, I get slightly more than 2.2° because I tolerate some vignetting.) On reflection, a shorter focal length would lead to a wider field but the trade off is in image brightness.
So that pretty much is the limit of what's possible with binoviewers. If you really want a wider field, a binoscope is the way to go.
If you need better info, the first step is to measure how much focus travel you have.