Thanks and Donation incoming. You're a legend
Sweet, many thanks! I'm glad you've been enjoying; Reverse Factory is my first and longest-maintained mod, one of my personal favorites, and even though it has been made partially redundant with the introduction of the Recycler in Factorio 2.0/Space Age, it still holds a special place in my modpack.
Output fluids
The problem is moreso the lack of proper automated fluid handling in the game. This problem somewhat affects input fluid as well, though to a much lesser extent. But the issue is the pipes themselves; once they have a fluid in their "network", the pipes themselves refuse to accept any other fluids, until they are manually cleared. Pumps don't fix this, because they technically become part of the system.
I think with Alt mode enabled, you can see the line that represents the network overlaying the pipes and pumps and even the machines themselves are all part of the network, so even if you try to consume the fluid, the network itself is still "contaminated" with the one specific fluid type. This prevents the Reverse Factory from outputting fluids into that pipe network, and eventually clogs the machine, until the pipes are manually cleared.
You'd need a fluid manager, or fluid sorter, or some kind of custom scripted machine that can manually separate pipe networks, in order to allow the Reverse Factory to function properly, otherwise it will just constantly become clogged whenever it produces a fluid output.
Older versions of Factorio (before the fluid network changes) used to allow individual pipes to actually hold different amounts of fluids, and simulated that flow in a different way; that was the only reason fluid outputs worked. The new fluid network changes are absolutely better and more efficient, but unfortunately also more "clingy", preventing multiple fluid types in the same network, and thus preventing fluid outputs.
