Actually, you asked if you were going to have problems. Using unsupported drives, there is no way to say one way or the other without having done it and tested it with the exact same make/model and use case you have. Doesn't really matter what you are using it for, there is ALWAYS the "possibility" of issues with unsupported hardware, in particular using consumer or NAS drives because of the low-power "features" and lack of programming for enterprise commands.
There is not a set "maximum" size. The 5TB size listed in the specs was the largest certified/validated size Dell sells in its configurations as of the date the manual was published.
BIOS updates may certainly help if the drives are connected to the motherboard (or the controller firmware if connected to a controller). While those types of enhancements are "usually" documented in the release notes, they aren't always. None of the current BIOS releases for the T130 mention anything for drives.