Fast Layer-4 iApp Template?

not totally getting the exact question, do you configure all your virtual servers with fast layer 4 profile?

then the iApp is probably largely not relevant anyway, because all things above layer 4 (caching, rewriting, ...) won't be possible.

in your case using a iApp isn't that useful anyway, just create the nodes, pool and virtual server and go.

also limited irules are possible, but not for things above l4, see: https://devcentral.f5.com/questions/what-exactly-does-fastl4-profile-do

so some throttling might be possible, depending on the events you want to use.