Recently, indexing from that particular forwarder has gotten to be even slower, sometimes falling hours behind. I'm curious as to what the recommendation from the community may be:
Our version is 7.0.2
You'd have to create local/limits.conf and then set It to 0 if you want unlimited. You also may want to consider increasing various queues (parsing queue) if your dealing with a lot of data.
Last you may want to consider increasing the number of pipelines. Get some more firepower In there! Just know it comes at a cost on your remote system (system with the universal forwarder installed).
Did you check to make sure the forwarder has not hit the throttle limits? maxKBps as per "maxKBps option and limiting a Forwarder's rate of thruput" or the limits.conf file