Not that it is of much use, but I tried doing the same in my Impreza, and frankly it didn't work at all.
When switched on, the full beams were clearly visible outside the car insofar as you could tell there was an extra light source visible in the headlight assembly, but the light had such a wide scatter that from the driver's seat it just looks like the main beams get ever so slightly brighter. This was with items from Autobulbs Direct in Southampton.
It seems to be an inherent problem since the turn of the millennium, as just about everyone I know with a '00-on Subaru complains about the headlights and full beams.
I'll be watching this thread with interest, however - this is something I'll be researching once I've collected my SG.
I will be retrofitting projectors for the dipped beam but I am not spending loads on the full beam for the amount of time it gets used. Just after something better than whats in there a the most efficient cost/performance
LEDs and HIDs in headlight enclosures that aren't designed for that type of output just causes light scatter and you wont see much of an improvement -If any
You're best off fitting some driving/pencil beam lights if you're after better High Beam only performance.
Projector retrofit is the way to go generally for a cleaner appearance
From amazon -- [ame]https://www.amazon.com/gp/product/B06XHD78DQ/ref=oh_aui_search_asin_title?ie=UTF8&psc=1[/ame]
These are quite blue, but much brighter than my prior Sylvania halogens. They have no moving parts (no cooling fan like lots of LED retrofits). I like that.
They have made it about 11 months.
I like the brightness, hate the color, but actually, on a relatively long trip of 5 hours in the dark, once I got used to them, the visibility was good. The low beams are acceptable, high beams throw well, though not as perfect as a built for LED or HID system.
I've tried many types of upgraded bulbs, including 100 watt halogens, Silverstars, etc. The best by far have been the HIR halogens. Short of an HID retrofit they have been the best plug and play option. Excellent beam pattern, no excess heat, no boy racer blue color.