Yea, I know what you want to do.
But anyway, I would stick to 1.0-1.2 EC and in early flowering still using the same EC but less MC and more MKP (it's cheap as plain sugar). Because MC lacks of P in flowering, and also has a little too much N for flowering, thus lowering MC and slightly upping MKP is way to go.
Anyhow, I am here for a ride!
It is nice test, you should think about EC that don't burn young roots and that the same EC fill pass through preflower stretch when nutes are needed the most. So with autos I will guess that there should be visible signs around 40-50 days. Good luck!
As I posted above, I recently planted unsprouted seeds directly into top feed dwc (2 multiple plant reservoirs) with max lights (about 40" away) and max nutes ( EC ~ 0.9).
The plants started slowly because of low res temp (~70 F), but they handled the max nutes and max light very well, and are now thriving.
I did make sure the top feed squirted far from plant stems, and hand watered with distilled and/or 100-200 ppm nutes for a few days to keep Rapid Rooters moist.
This allowed the roots time to acclimate to the max nutes that were wicked up into the hydroton.
The young leaves acclimated to the max light as they were sprouting, and the sprouts didn't stretch, as they had done under less light.
It might be possible to greatly simplify dwc grows by doing several unorthodox things:
1. Plant seeds directly into Rapid Rooters, and immediately put them in a max nutes reservoir, while hand watering for awhile.
2. Use max lights and a single ppm from the time they are planted until harvest.
3. Never ever change out the reservoir unless problems arise.
4. Use multiple-plant reservoirs, and not worry about different nute and light needs.
Adding an external reservoir with float valve can reduce dwc workload to about 0 - 15 minutes average per day, and adds the ability to leave the system alone for a few days.
Preliminary indications are that all of these things do work.
I'm about to start week 10 (or week 7 with the late-planted seeds) with 7 different strains, and haven't ever changed the reservoir at all.
So far, I see no difference between never changing, and changing weekly/biweekly.
The easier growing is, the more people will do it, and dwc can be made very easy.