Update: In case someone else comes across this in the future.
I set up my tank approximately 2/18/2020 with ADA aquasoil amazonia light. Yesterday on 5/1/2020, my tank is converting 2ppm Ammonia to Nitrates in 24hrs. So, I had successfully cycled an aquarium with a PH of exactly 5 ( courtesy of PH pen meter), and negligible KH. I just recently started weekly water changes to try to keep KH around 2 by dosing GH/KH+, although the buffering capacity of the soil strips it all in ~48hrs.
Super excited to get back into the hobby.