Genuine question: given this, am I correct in thinking that if there was a big corporate tax cut the most likely outcome is that the money retained would just further inflate this savings glut?
Cutting one time brings back lots of capital to invest, lots of that will be paid to shareholders, who will spend some and reinvest some. With similar effects, for that year.
(And yes, I understand that the cash isn't just stuffed in a mattress, but it's an important distinction that the money isn't being invested in the direct sense)