Adjusting the sealers gloss level.
It depends on the sealers. You cannot do that, except with "SBS Sealer", "Porous Stone Sealer", and "Mexiglaze". "SBS Sealer" is the lowest solids ( lowest gloss ), "Porous Stone Sealer" is higher solids (higher gloss), and "Mexiglaze" is the highest solids ( highest gloss ).
The options are:
Can you blend two sealers to adjust gloss?
Yes, with the above same sealers - SBS Sealer, Porous Stone Sealer, Mexiglaze.
You can use lacquer thinner to melt and remove some of the sealer solids on the top that create the gloss level. This will take a little experimenting with brush and rag to get what you want as a technique. Generally, the best way is to pour a puddle of lacquer thinner and then swirl it around with a brush before it dries. This is to see how much of the solids can be encouraged to penetrate down further into the surfacing.
If you stop brushing while still liquid, it should have enough time to flow out and self level again so you do not see brush marks.