Oil + additive viscosity

Yes. Might as well. At least ease the entry.
As long as you don't open it so much as to weaken the fitting itself, it can't hurt to reduce restriction here.

Based on what you posted, the drop in flow is related to something different when the system was switched over to the 360.
FWIW I ran an remote filter for a few years. And even when the oil temps went close to 300*F, did not have the presure drop off with rpm.