I think best approach would be to use different VLANs for each protocol. Then they are layer2 isolated.
The IPs are autoconfigured according to the MAC address.
For instance, and IPv4/IPv6 scheme would be the next (EE:FF are two last MAC bytes):
OLSR: VLAN1 10.0.EE.FF/16 fdfe:aaaa:aaa0:EEFF::/64
BATMAN: VLAN2 10.1.EE.FF/16 fdfe:aaaa:aaa1:EEFF::/64
BMX: VLAN3 10.2.EE.FF/16 fdfe:aaaa:aaa2:EEFF::/64
BABEL: VLAN4 10.3.EE.FF/16 fdfe:aaaa:aaa3:EEFF::/64
The tests can be performed sequentially or in parallel, it would depend on the kind of experiment. However all nodes must be always reachable using all protocols.