No and see no reason to.

I'm still testing every couple of mixes (finding pails are consistent top to bottom btw so will probably do what Rob Reefer says, test at the start of each new pail) then since I know where I'm low, I'll supplement using bulk Mg and Ca (plug to littlesilvermax). Figure supplementing adds about $5 to the cost of the pail and maybe a extra 10 minutes to make 20g of SW. Doing this, my Ca and Mg is where I'm shooting before I even add it to tank.

Great idea, thanks!

Should I be bringing it up slowly....when I do the water change with the higher Ca/Mg do it over a longer period of time? I would guess because of it only being a 20% wc, it wont be too big of a shock to the whole tank.

I will be sending littlesilvermax a pm as soon as my kent runs out, which wont be long, I have heard nothing but positive feedback!

You can bring the levels up over a couple of days with no problem.
BTW here's a Reef Chemistry Calculator just in case you haven't found one yet.