Be careful! The last Techs produced have only corner tabs on the bottom of the razor's cap to keep the blade in position. Both the blade and shim must fit within those tabs. To answer your question though, shimming a blade and thus increasing the blade gap will increase aggressiveness.
If you haven't done so already, I suggest you try a really sharp blade like a Feather in the Tech. I like aggressive razors, but the Tech with a Feather is all the aggression I need. BBS is as good as it gets, Baby!