Feeding the oil filter cavity with ambient temperature oil is nice, but what temperature is that small volume of oil going to be when it gets around and over and up and over and across to the cam bearings? The castings are all at engine operating temperature, so I suspect the cooled oil is too by the time it gets up to the head.
If he didn't block off that cases/cover passage, he has a 50/50 mixed bag of input oil temperatures actually feeding into the oil filter cavity. Half will be ambient air temp and half will be engine operating temperature.
It all comes down to the same old quandary, to be safe you keep the pressure high (volume low) and get very very little effective cooling out of the rig.
If you want a lot of real sump cooling effect, you need a separate high volume low pressure pump that just moves a ton of oil from the sump up through the cooler and back to the sump, circulating repeatedly.
You do know the SV650 uses aimed oil jets to blast oil streams on the bottom side of the piston crown -- Suzuki calls it the "Suzuki oil jet cooling system" and they use it in all their high performance engines.
I don't think the Savage has that "Suzuki oil jet cooling system" with the separate aimed oil nozzles and all -- we likely just use a slinger system that takes the post-use eccentric crank pin lube flow and slings it up to splash lube the piston and cylinder walls.
Just splash lube, no intentional piston crown cooling.
Supercharging and Nitrous will both overheat the center of the piston crown and we do have us a beer can sized piston dome to deal with ....
...... with it getting all hot and softening some in the middle .....
bet the top ring groove area expands a whole bunch more than normal when boost is high, too