With inlet builds your reactor now needs to be able to hold more heat than you are producing otherwise it will overheat and meltdown. However I have found a bug where if you have your inlet system set up with sufficient plating and cooling, you can pause the game and remove all of the plating and when you unpause the build will remain stable until the reactor heat is updated, either via addition or removal of power cells, inlets or outlets.
I suggest updating the UI for in reactor purchases, instead of having Next Page and Previous Page buttons, there should just be tabs which take you straight to the page you want to purchase from.
I think Protium should have upgrades specific to it in the Experimental Component's shop such as Enriched Protium, but for a cost of several thousands of exotic particles just for the first upgrade.
It would seem that people don't understand what prestige means, when you prestige ALL of your current progress RESETS but you get exotic partials which are used for permanent upgrades that last through prestige.