Yes, that works too. In my case command line would look like:

bfgminer -o <pool address> -u xxxxx -p xxxxx -S \\.\COM5 --set-device \\.\COM5:clock=x0981 -S \\.\COM6 --set-device \\.\COM6:clock=x0A81

In the context of performance, I'm not sure which way is better.

It turned out to be quite simple.

I'm running now 2 bgfminers in 2 command shells with something like -S amu:\\.\COM5 --set-device antminer:clock=x0981. I found corresponding com ports in Device Manager->Ports. All other BFG settings can also be adjusted for each session.

Hello,
I'm running BFGMiner with two Antminers U1 and U2. One of them works well with 0981 max and another one runs nicely with 0A81. Is it possible to configure BFGMiner to set different overclock values to these devices in command line or configuration file?
Thanks!