2 LACP paths to 2 switches without spanning-tree

Ah, I thought you meant on the F5. That being the case, you can do this but you'd need to ensure the connections between the F5 and the switches are loop free (no link between the switches for any VLAN the F5 is in) or layer three (routed). In either case, all the links will be active at once but with the layer three method how you setup your routing will influence which links are actively used to pass traffic.