The suggestion of recipe is pretty good. RO water is fine as the nutrients are added in the recipe.
Most recipes that suggest boiling are derived from old recipes when it was necessary to sanitise the water more than the honey. We dont have to worry about that now do we and we also know of the detrimental effect of heating the honey - unless making a bochet, which rather different.
So I'd suggest making up the must to something like 1.100 and if temp control might be a problem, the K1-V1116 suggestion is probably the best for ease of fermentation management.