You have me curious now. How stiff are the OEM springs, that the Taran pads don't need stiffer springs? Do they feed reliably?
My plan was to find a G43 and add the +1 pads ASAP.
I have the TTI +1 and +2 with no issues yet. The +1 is only slightly longer than the OEM part.
They work just like the +1 and +2 extensions work on a fullsize Glock with OEM springs.