Question about Daly Smart Active Balancer

[ZEUS-FL]

Can I buy a 20S Daly Smart Active Balancer with BT and use it for only 7S at the moment? Just connecting B- to B6 + B+ on 7? Will read only 7S and work? Also the same question with BMS. Can i buy a large 20S BMS and use it for 14S for example?
The idea is has the ability to be use for future larger projects. I was watching this video and it looks like is what he is doing.

 

[MisterSandals]

Can I buy a 20S Daly Smart Active Balancer with BT and use it for only 7S at the moment?

No, not unless it specifically says it will work for different numbers of cells.
The way you describe would lead the BMS to believe cells 8-20 have zero volts and disconnect as designed.