What is a EB engine? I think you mean FB25.
We are on our 8th Subaru. Most have been foresters with EJ and FB engines, though there was a SVX and a Justy in the mix
I've tired all kinds of oil - but formulation are changing.
Had a lot of consumption with the Pennzoil Platinum, Wasnt enamoured of the Valvoline Advanced.
Subaru Synthetic is good though it used to be a very thin 20 grade. Had reasonable luck with Mobil 1 EP which is purported to be a real high group synthetic.
I am Running Magnetec 5w20 in the FB20 no issue there other than the usual dry start.
But I feel the the convenient though questionable inverted filter is going to kill the timing system regardless of what you run.
The Fram-a-roo Blue service part filters empty out in a couple of minutes after a hot shutdown and the engine has horrendous chain noise for about a minute after start. The engine didn't do this when new with the Factory Toyo Roki filter.
Good luck and if you get timing noise go back to the dealer service and hound them. Dont let them pass it off as a "subaru sound" This engin eis silent as anything when operating properly - the FB series has hydraulic lash adjuster so no tick tick and piston slap as in the wonderful , superior oversquare EJ engine. Yep I liked that motor.
Good luck. - Ken