1/4 tsp per 6 gallon on the sulfite still is really light in my opinion but then when in pill form there may be a lot of filler. Someone else may chime in but generally the package directions should work for the product they are intended for. The sorbate however I think you would be good to go with what FB and I said at 1/2 tsp per gallon.
A painting says a thousand words. But a painting while on good mead just looks funny!