Timing chain adj is automatic. There's a teardrop shaped black rubber block with an internal spring for tension. I don't think oil pressure acts on it too. The tension side of the cam chain runs against a rubber coated flat guide. There is no guide on the slack side, iirc...

The balance shaft chain adj in stock form is an oval bolt slot in the bottom leftish bs chain guide. The guide is secured by a bolt at the pivot and a "special" bolt with a high hat 10mm head (maybe 12mm) in the oval slot, so you could loosen that special bolt and using the hole under the timing cover small cover you mentioned, push up and inward on a tang on the guide to push it into 1mm clearance from the chain with the eninge warm. When installing a bse kit, I dremel an oval into the new, and only, guide in the kit, so I can "tension" the new short oil pump chain on the slack side. This short chain can make slapping noise if the tension is far out. The long oem chain surely can stretch and slap. It's almost twice the cam chain length. Even if you didn't oval the cetralish bolt hole in the bs/oil pump short chain guide, there's often enouch slack to at least pry the new guide closer.