You can log 100hrs of Level D simulator if you want to unfreeze your ATPL.
So 1400 hrs flight time & 100 hrs Level D sim is enough for your ATPL. But level D sim hours do not account as total flight time! (Otherwise you could for example obtain you're ATPL with 150 hrs real flight time & 1350 Level D hours
....I know it's not realistic, but just to make a point)