The rule of thumb is to span the stencil aperture by 5 solderballs. My analog switch has a 0.2mm stencil width for the pins (it is a 10-pin QFN). T3 solderpaste largest ball is 0.045mm, so that is less then 5 balls across. T4 is 0.038mm, that fits okay.

It costs 2 bucks more for each 5cc syringe I use, a normal and a low temp solderpaste. I get them from Chip-quik. The bottom line is whether it works for me or not. So we will have to see.