I understand packed snow blocks are meant not to melt, but with a mod like fabric seasons, the regular snow comes and goes, while the layers of packed snow that had been formed by iron golems sticks around well past winter until I break the blocks one by one. I posit that if these layers melt already, then they ought to melt faster, or at least have a config option to toggle the layers from forming when iron golems step on snow layers.

This is a feature of Frostiful, assuming you are on 1.21.x. Packed snow will decay to regular snow, and will do so very quickly when the ambient temperature is above freezing. There is also a config option called something like enableSnowPacking that disables ravagers and iron golems from packing snow, which should be on 1.20.x.

If you are in 1.20.x and packed snow melting isn't there, then I will probably not backport it since 1.20.x is not supported anymore.