Making the Lancer much rarer- they tear through fighters and bombers, but then thus completely neutralize the NR's main strength. Making it an occasional super unit would present a challenge on some worlds, but allow the NR to occasionally use fighters in a battle without seeing more than 50% rates of attrition. Endless Lancer reinforcements from a shipyard can get impossible to wear down.
Lancers are pretty easy to focus down so I'm not sure why we would need to artificially limit them. You can pretty easily avoid them with your fighters if you need to, and get other ships to take them out first. If you focus fire from bombers, they die pretty quickly from the fighters themselves, too. Station garrisons are being changed for 2.2, so the anti-fighter counts will likely be lower, but really stations aren't difficult to take down in the first place, most frigates can do it on their own. Garrisons are being limited in the same way ground garrisons are anyway.
Perhaps a few systems where there can be no infrastructure? Thus golan spam and shipyards calling in endless reinforcements would be slightly rarer.
That make a lot of factions non-viable in a lot of GCs, or we'd have to do different variants of each planet depending on the GC. Most planets are limited to Golan Is, and only two slots. Removing infrastructure like that basically just turns the majority of the map into even more of a pointless no-man's-land.
Some more early era NR v IR scenarios sans Pentastar? If they are meant to be neutral, it seems a little weird I keep getting pincered by both the Reaper and Lusankaya.
Thrawn Campaign has tended to fill this niche of a straightforward NR vs IR scenario early on since there wouldn't really be much different about an era 1 one. Bacta War sorta fills where Fractured Empire was, although Zsinj is there.