Reactant drop rate is too low on endless missions

[KesslerCOIL]

In endless missions like Interception or Excavation, unless you take it extremely slow and try to let as many enemies possible get corrupted, you will never have 10 reactant in time. It's ridiculous that you have to handicap yourself in order to actually unlock a relic and it's why so many prefer doing Captures, when you can get 10 reactant and complete the mission 3x over in the time it'd take in an endless mission.  
On missions like Capture, I frequently get 10 reactant in well under a minute so there must be something tweaked differently in the endless missions to cause this reactant famine.
There absolutely needs to be at least 1 guaranteed reactant drop per corruption spawn.

Edited August 18, 2019 by KesslerCOIL
Additional clarity