Hmmm. The way I read it, I had assumed that you were changing the 'Level' parameter itself. That would not work because the 'Modifier' would take priority. But changing the 'Max' parameter in the 'Edit Modifier' window should work???
I know that the modifier settings are saved with the block when using the 'Blocks Library'. This 'Global Block' behavior is either 'intended', an 'over-site' or a 'bug'?
My 'Filter' work-around would work, and you get the added benefit of adding a small bump in the mids when you boost.