Curious if i could transplant 6x6 grodan cubes into 5 gallon pots with coco .. with no issues?

For my next run I was thinking of vegging in 6x6 grodans... Then once I get to were I want them transplant them into 5 gallon pots with coco wait a few weeks in case they stress out maybe?? Then flip them to 12/12 has anyone ever done this before? I don't see why It couldn't work could , reason for 5 gallon pot with coco idea is so they can stretch there legs some more during flower??? Has anyone ever done this an if so how did you like the 2 medias together ?

Some of my friend's have been doing it this way since CoCo Coir came out.They do it in a table and have very long root's though..

Ok and the veg in 6x6 cubes then add cocoa an pot for flower?