There are so many choices, and most of the pickups available can sound really good. The topic of pickups is so subjective.
I find the Anthem hard to beat as a recommendation for a 12 string pickup. I have performed with all the Baggs pickups (save the most recent HiFi Duet) in my 12 strings over the years (LB6, Element, Dual Source, iMix, iBeam, Anthem, Lyric and even the M80), along with a Fishman Matrix, K&K Pure 12, Sunrise, and several others I’m surely forgetting.
I currently have a 12 string with a JME Ultra Tonic installed (think: K&K plus onboard feedback suppression, balanced output, and volume wheel), and another 12 string with a Trance Amulet M-VT Phantom. The Amulet (phantom powered) and Ultra Tonic (passive) are neck and neck for the cleanest sound ever, as in super-clean, with the edge going to the Amulet as both my favorite and for being the most finicky to install. Either of those pickups are stellar choices! However...
By contrast, the Anthem deliberately adds some “color” to the sound. It’s warmer, and has more bottom end, straight out of the jack without extra processing. That can be nice for someone who wants to plug into an acoustic amp, for example, and get a really full, rich sound without adding anything. Is the Metropolis Mahogany and Cedar? If you like the sound of the Anthem in that guitar, I would guess you would like it in the Maple Guild.
With my foot poised to go directly in my mouth, I might suggest that a super clean, pure sound in that Maple may sound a bit brittle to you. Just a guess.