Glu Lam Beam Sealer Recommendations

I am an Architect working on a 30,000 SF, one-story building in Cheney, WA. The Owner of the building, now in design stages, has some concerns about sealing approx. 6 ft. lengths of 21" dp. Glue Lam Beams exposed on the exterior of the building. The beams are under a roof overhang - eave - in most conditions and the end of the Beams will have metal flashing caps. My question is what is a good sealer that will stand up to harsh sun (UV) exposure - east and west building exposure on the beams. Would like to stick as close to the natural wood color as possible, but can look somewhat different from the finish on the GLB at the interior of the building. Should I go to a marine grade sealer (like Sikkens Cetol SRD) or something that penetrates the wood (such as Cupronal - Sherwin Williams product). The Owner is concerned about a product that has frequent maintenance. What are my best options? Also looking for some good project examples with this type of sealer in use for several years, that the Owner can look at in the Seattle area (GLBs or equivalent).

I have been a carpenter in the western Washington area for 25 yrs and have been fighting with these details for years. And I should point out that the cause of the detail has often been my own suggestion, silly me.
The only guaranteed solution is not to expose the beam at all, but I assume that you’re past that. In as much as you are on the east side of the Cascades you probably would not have to worry about rot as much as we do this side. I think the problems are more differential moisture content (waterlogged to over-dry end grain) and sunlight.
Regarding the moisture I note that you indicate the beam depth is 21”. At that depth
it will not be easy to keep the bottom of the beam dry with a cap flashing. Have considered a flashing to cover the beam end entirely? A copper flashing has the added advantage of preserving the wood where it leaches.
Another important detail is to make a drip cut across the bottom of the beam about 2”-3” from the end (¼”wide ¼” deep) to prevent water from making it back into the weather shell.
Lately I have been using penetrating epoxy on endgrain before applying other sealers.
The epoxy seems to act like a primer coat on the ends and does not interfere with
Other finishes (though I would try it on scrap first)
As to the ultraviolet, pigment is our friend and I know that Sikkens uses some; to me it looks rather yellow. Other products claim to block UV but I would be interested in a track record.
I would be interested in the results of your search, I hope you post it.