I would only expand the oil capacity if there was a really good reason, maybe a race car for track days or a dedicated 4x4 in steep terrain.
My 4Runner 4.0 V6 takes 6.6 quarts. That's a lot of oil. My T&C 3.8 V6 only takes 4 quarts.
I'm sure Toyota increased the oil capacity 4Runner 4.0 based on design criteria such as making sure the sump doesn't go dry when ascending or descending hills while 4-wheeling and as a result of the larger oil capacity were able to extend to a 10K mile OCI. There's not a lot of room under there to increase it more without sacrificing ground clearance.
2019 4Runner 4.0L, 18K Mi, M1 EP 0W-20, OEM
2010 CR-V 2.4L,100K Mi, M1 0W-20 AFE, M1-110
2009 T&C 3.8L, 130K Mi, ST 5W-20, Fram
2006 Cobalt 2.2L, 184K Mi, ST 5W-30 HM, Fram