That spec is certainly not written in stone. With GI, i've started at 2 and added 2/10 for each cascade...with SA and C-Cor I've added .5 and started with 3. Often varies with age and the system head tech. I assume you're sweeping GI, because you mentioned a BDR board. Getting .5 with GI is a real gift. It may be necessary to tweek the BDR, especially if it's been swept before. You can bet that it's already been tweeked and maybe not in a correctice way. If you have an unusual response, make sure to check your input response before tweeking.
This is CABL.com posting #328043. Tiny Link: cabl.co/mbxvb