All you need to do for your DE deadlift, Hits, is to start at around 50% of 1RM (with good form, no back rounding) and move up through to around 70%, adding 5% to each session as you go
. This way you will be working in the strength-speed continuum and it will erase this problem with it feeling light as a feather, lol. When you get to about 60 it really won't feel very fast at all...just remember it is the intention of moving it as fast as possible that counts. Since it is 'strength-speed' it is more "strength" than speed...you just emphasise the EFFORT part of dynamic effort.
This probably will be the most useful thing for you right now, imo and is the most sensible way of doing it.