If you pull the intake, carefully examine the intake gaskets for distortion around the intake ports. Look for mushroomed / swollen gasket material at the bottom edge of the gasket. Ths would explain oil getting sucked into the cylinders.

With an external oil leak at the front or back of the intake, this can usually be traced to the intake end gasketss (intake to block). Some of the less expensive intake gasket sets have the end seals made of cork and these shrink over time and are guaranteed to cause a leak.

Yes some people do skip installing the intake end gaskets and just use a bead of silicone.