It has come to my attention that if I try to store a DST in my Rorqual ship maintenance array with heavy water or isotopes in the fleet hangar. I get a pop up saying that I can not do that. However I can have stront, liquid ozone, boosters and ammo in the fleet hangar. The heavy water acts as a charge when used with the industrial core. So it meets the same requirements of strontium and Isotopes are used as a charge to initiate jump drives.
I think heavy water and isotopes should be added to the list of items allowed in cargo of ships stored in ship maintenance arrays. It would be a simple change, and make it easier for Rorqual pilots to be more mobile with their mining.