This is being way over thought. You can use ANY regular servo, digital or analog with that receiver. When we say "that receiver", that means receiver. Mode is irrelevant. If we were going to mention a mode, we would have.

The R2008SB receiver operates on FHSS mode when an FHSS transmitter is present, and S-FHSS mode when an S-FHSS transmitter is present. It does not "care" which servos you use. However, you MUST use S-Bus servos on the S-Bus, or an S-Bus decoder when you use other servos.

Again, we don't know where the idea came from that FHSS and SFHSS affected the servos.