Yeah. And this phenotype I am growing has always been a heavy feeder. from day 1
Have you contacted your water supplier and found out exactly what is in your water?
If that were my plant and I was having those problems under those circumstances, I'd try to get the unknown variables out of the question.
That would be:
1 - run RO water and feed at 1.0-1.2 (now you'll know exactly what is in your feed)
2 - do an initial flush at 1.0-1.2 EC until what comes out in runoff EC is what is going in through the top (now you will know the entire medium is "reset" to the appropriate EC)
3 - continue to feed (same EC as above) at least once a day to 10-20% runoff (this will ensure your rootzone EC stays consistent)
4 - ensure all feeding (including the initial EC flush) is done slowly and evenly (this will ensure there are no valleys in the medium, preventing inconsistencies in the rootzone
Or, instead of using all RO water, you can do what 7Card said and water down your tap with RO water until your starting tap is 0.3 EC and then follow the above steps.
The least best and lazy option would be to add 1.0 EC of feed to your starting tap and feed at 1.6EC and do the steps.
One other thing is when you transplant, the roots don't need to grow into it. Just feed at least once a day. Coco/perlite, if prepared properly, is porous enough to get enough oxygen to the roots. In fact, I feed daily 24 hours after the seed pops up in the coco and never hit the brakes.
