I haven't used the 50pk variety I'm afraid ... knowing Verbatim, it is entirely possible that those will come with a different MID...
EDIT: Just spotted a post from katraine (here: http://club.myce.com/f87/verbatim-6x-question-pioneer-drive-335806/) saying that Verbatim Datalife 43804, 43811, 43812 all use the CMCMAG BA5 MID, so you might want to aim for one of these ... it looks like the 43812 ones use the CMC MID.
As with most BluRay drives nowadays, there are no unofficial/custom/patched firmwares available at all for these drives.
Crossflashing is possible.... details in this thread (see 'method 3'): http://club.myce.com/f87/asus-bw-12b1st-rebadged-lg-bh14ns40-version-not-liteon-ihbs112-version-335096/
ASUS is a disaster lately when it comes to releasing firmware updates. LG has released two updates for the BH16 series since the drive's release, so by crossflashing you gain access to the latest firmwares and all the improvements they bring, including better media support.
If you contemplate crossflashing, just make sure that you do a firmware dump before crossflashing, otherwise you won't be able to revert back to ASUS (because ASUS haven't released any firmware updates for this model yet). A raw firmware dump (which requires manual processing before it can be flashed back) can be done with DevilsClaw's Flasher, or give Dosflash a go (it might produce a full dump), or do both ...
Even if not crossflashing, it would be great if you could do a dump anyway using both Flasher and Dosflash and share them with us