Seems like you have a bunch of anthem effects going on. Have you considered Marshal's Anthem? With the kicker cost you can get something back from the graveyard which is always useful. Angel of Invention is another anthem on legs, and with your slight angel tribal happening here, you could always try to reduce the cost of casting Gisela and other creatures with Urza's Incubator and just use tribal anthem effects as well.

Ramp is always kind of hard in these colors. You already have land tax which is great, but you could also consider Oreskos Explorer and Weathered Wayfarer.

Thanks smiffdemon for your feedback!

I like all of your suggestions. tbh, I hadn't really considered adding more ramp than what I have already. There's definitely room for it to ramp faster--it just hadn't occurred to me since my play group plays moderate to slow decks and we play a lot of multiplayer, so this deck usually doesn't have any problem keeping up or outpacing them. But I could be in for a rude awakening if I go up against other, faster decks, so I'll bear those ideas in mind. (I did used to have Weathered Wayfarer in there--I think it got cut simply because I needed a cut and I never seemed to draw it.)

If you have a slower meta then there's no need to put in too much ramp. Wayfarer is invaluable though, since you can tutor up any land basic or not every turn.

Yeah, you're right. Actually, I'm not sure why I cut it over Expedition Map. That will probably be what I drop to make room for it, even though you have to have fewer lands than an opponent to use it.

Generally with Boros, it wont be too hard to activate him. Esp if anyone at the table is playing green.