But with the proper LEDs (proper as in correct spectrum, ideally peaking around 450nm and 680nm), 20 micromols of PAR will be much more effective than let's say 20 micromols of PAR from a full-spectrum bulb which from the spectral graphs I've seen tend to have huge spikes in the green-yellow range (which isn't completely wasted PAR, but it's definitely not as efficient for photosynthesis). So with an efficient LED fixture, 20 micromols PAR can easily put you in the high-light range.
So then to see the best plant results I'd probably want to be around 40 or so with the Fluorescents it seems. I think I'll figure out a way to suspend the light a bit to achieve this and then battle any algae problems if they arise. Luckily the tank will have time to develop before any fish are added so I'll have time to get whatever algae help is needed and go from there at first.