Don't you always have at least one shift with spontaneous magic?
When a spell discharges into something else - like it did for Zuno with the mind bullets - is that basically shifting points from the primary discharge into the secondary? As in a 2-2-2 with 3 shifts could produce two 1-1-1 discharges?
http://lemuria.org/SM3/welcome/freeshifts are within the spell details - the sum stays the same. So a 2-2-2 spell with 1 shift could become a 1-3-2, 1-2-3, 3-1-2, 3-2-1, 2-1-3 or 2-3-1 spell. Intent and Base always stay unchanged. However, instead of shifting inside the spell, or discharging into something with a PL of the number of shifts.