I do have a lot of concerts in bluray and I do need full BD Menu support....for me MKV'ing is a blast and personally I have never been a friend of the MKV format. Currently for BD the use of TMT5 has proven to be the best bet to display full BD menus or watch 3D BD. Now whilst you could build in a switch with a custom filed and a calculated expression I guess (i would be unable to explain exactly how to but some forum users (which are expression building experts) can certainly chime in to help you) you might be able to have MC launch some of your BD's directly and some with an external player (TMT5).
I can only report for the usage of TMT5 as external layer for ALL blurays.
I had to store all the blurays in bdmv (would also work with iso) and then :
You need to point TMT5 as external player to the containing folder (or to the disc drive if you read from physical BD) (= 1 directory level above the bdmv folder) and not to the bdmv folder itself or the index file in the bdmv folder. If you have this structure for example : my bd/movie test/disc1/bdmv you need to point to disc1. A way to do so in MC is to :
1. select tools>options>library&folders>manage library fields
2. add new field (I named it TMTLauncher)
3. set the new field to calculated data and construct your structure line. Here you could enter expression filevolume([filename])/FileFolder([Filename],2)/ ... (it will depend if you want to use relative paths or not - (display this new field in your library and check the result) remember you'll have to end up with the path to the folder holding your bdmv and certificate folders.
for expression building consult :
http://wiki.jriver.com/index.php/Media_Center_expression_language.
4. once the result of your expression is OK return under file types (in the MC options menu)
5. select video bdmv
6. choose external player (custom) under playback method and point to the tmt5 player (you can also try to point to the uMCETMT player which opens and closes fine and is better when using theaterview - auto refresh rate should be disabled in TMT because if not closing it freezes TMT/MC or 3d engine lost error appears)
7. under arguments enter "[TMTLauncher]" (thats the field you created under point 2)
That's it !!! works perfectly. Seems complicated but in reality it isn't. Just make sure you got the path naming right....and you have full menu support for BD.