Can't answer your question about V700/750 since I don't own one BUT I thought the standard for 6x6 was to cut 3 frame strips not 4!? Where do you store your strips? I know no negative sleeve (and file) that will be able to fit 4 frame strips of 120/220 film... Maybe you should continue with 3 frame strips in the future. (I personally have only one roll that was cut into 4 frame pieces, and that was my very first 120 roll!

)
OTOH, I don't think that you'll have to cut 4 frame strips to be able to scan them with a V700/750, since the holders should allow you to mount even longer strips. (According to my experience with other Epson flatbeds, that is.)
You can also buy a Betterscan holder, they should fit 4 frame strips. See this:
http://www.betterscanning.com/scanning/vseries.html
("...Each of the two film channels can scan 213 mm from each of the two strips in one pass (this is the actual image length that can be scanned in one pass) and the film channels can hold/accommodate film strips up to 240 mm in total length (again, only 213 mm can be scanned in a single pass without shifting the film)...")
OK. I did some search:
http://www.firstcall-photographic.c...learfile-15-negative-pages-6x6-cm-pack-of-50/
We don't have vertical sleeves here. Only horizontal (4 rows). So, apparently some like and prefer vertical film orientation (in negative sleeves) for square shots...
Regards,
Loris.