You're just dosing extra K.
...which is perfectly fine.
Also, don't forget to include K from KH2PO4.
The K provided by the K2SO4 in the recommendations is a very small quantity (about 2ppm last I checked) and presumes that the bulk of the K comes from the KNO3 & KH2PO4. These dosing recommendations are not necessarily in line with the recommendations that Chuck Gadd provides, as it comes out to being about 10ppm K per combined macro dose in general (again per memory of last time I calculated these doses).
One can also dose Equilibrium instead of the K2SO4 weekly at water change, that'll provide some extra Mg, Ca, Fe, Mn, and of course K. I toss in an extra 1tsp of K2SO4 (~10ppm) in addition to the 1tsp of Equilibrium when I do my water changes for my 75 gallon. Some EI dosing plans use the Equilibrium and some use the 3X weekly K2SO4, there really isn't anything wrong with doing both either.
Personally I wouldn't really bother with the 3X weekly K as listed here, the dose is too small to be worth the trouble -- just take care of it weekly. K2SO4 for solutions has a very annoying solubility limit too. That's just my personal opinion though. My extra K dosing was a bit of an unscientific experiment, inspired by my soft water and having done the math you're doing.