IMHO, Zelensky is more and more worried about morale, and he wishes to “cancel the negative waves.”
But I think he should live with the risk, given that, without a few thousand more artillery field pieces, plus 4 x that number of barrels, plus 10,000 x that number of accurate ammo rounds, Ukraine forces will have a very tough time just holding the line.
Ukraine forces are having a very tough time trying to hold the trench lines - absent artillery support, and absent small mortar fire support.
So, in some skirmish, might Russia capture US made Patriots or similar latest tech systems?
Oops (or planned).