I think a new type of token should be instituted called the consolation vault token such that whenever rewards could be earned but 20 iso is rolled a “consolation token” would be awarded instead. These tokens would open rewards from a vault which would be a watered-down DDQ vault. Most awards would be, say’ 50 iso, but maybe some single health packs sprinkled in, with some higher level awards being something like boosts and at the very top, something like 5 2* covers and say 1 or 2 heroic tokens, maybe even a chance to pull 25 hp. This would feel way better than just earning 20 iso since it gives more tokens to be opened, and the pretty much guaranteed chance of getting something better than 20 iso would really go far in making people happier.
To prevent people from farming easy nodes that have been 4/4 completed, you could make it such that these 4/4 nodes would still issue 20 iso when completed. I’d also suggest that the vault stay open only for a single PVE sub before getting refreshed, and that tokens expire at the end of the sub so as to not make hoarding a viable strategy for opening up all the stuff in the vault.
Something like this would make me much happier, because it would make me feel like I got SOMETHING for my effort instead of the current nut-kick award.