Using a normal forwarder instead of a lightweight one doesn't necessarily have implications in terms of licensing. Only if you turn on the "indexAndForward" feature on the forwarder - which would lead to data beeing indexed on the forwarder is self as well as on the indexer - would be a reason to install a enterprise license. You can configure this option under Manager -> Forwarding & Receiving -> Forwarding defaults.
You can of course filter the events before beeing indexed on the indexer (in case you use the LW forwarder). You just have to configure the transforms there. The only downside is that all events go over the network.