I don't know if you guys are familiar with Joes Ancient Orange Mead (JAOM) or not, so let me explain it. In JAOM, the recipe explicitly states if you change the recipe in any way, you void all warranty.
The BOMM is no different.
If you change, exclude, substitute, omit, or otherwise, it may not work!
It is possible that it will work, but no guarantee !
Edit: I use Ozarka spring water. I find trace nutrients in the water are very important for clearing and yeast health.
Potassium carbonate is extremely important. I would not start without it. I operate under the mantra "Do it right, or don't do it at all". I made a lot of mead before potassium carbonate and around 60% stalled. Never tried it with 1388, so all bets are off.