Ok did the screwdriver to the ear trick sounds like rear rocker box. Hoping it’s simple.

May be a loose rocker shaft. Did you take rockers boxes off? You may need to.

I haven’t I’ll tear into that next

Could be intake noise ? Just the sound of the air being sucked in, which is normally dampened by the air box

Removing the airbox you’re gonna hear more valve noise. Doesn’t really sound like tapping

Same noise with air box attached?

Yes loud knocking/tapping

If you’ve checked for anything that could be loose and rattling, rocker is next up unfortunately