I have read that directly connected does not utilize all the power the panel can produce due to amp rise / voltage lost as it will pull all the amps the panel can produce lowering voltage so I was hoping that would be possible with just a controller and a panel. Looks like not.
The best way to "optimize" would be to have a resistive load that dissipates max. power at or near the voltage you are able to supply,
Batteries of any kind present a completely different type of load than a resistive heating element. I'm not sure how the MPPT algo that's designed to see a battery would treat a purely resistive load. That algo wants to see the voltage of the battery bank as a basis for optimizing the panel output. A resistive heating element does not source any voltage.
Perhaps somebody can try it and tell us what happens.