new refinery worth it?

They are. But you should probably refine Wing Sword for a +Atk Caeda.

Caeda's Wing Sword refine gives her an effective niche against armored/cavalry threats, and it also gives her a Flashing Blade effect which would fit hand in glove with your character's boon—along with flier buffs, she'll make good use of that more frequent special procs.

They’re actually all really good, but... it depends whether you use them or plan to use them. So far I’ve upgraded Lucina for AA dragon slaying and Raven as I want to make a full build for him. I plan to do Alms upgrade and Caeda eventually for that wing sword so I have more armour counters for AA.

I say Hinoka's and Caeda's refinement are the most worth it.

Caeda now has Flashinig Blade and bonus damage against common cavalry and armored units, she is definitely worth using. +Spd will ensure she gets off Flashing Blade 99% of the time even against speed demons.

Marth's refinery is also great, but doesn't get a boost in combat; he becomes a potent stat boosting support unit instead, similar to Brave Lucina. If you're looking for a boost to the unit themself, especially in combat, go for Caeda instead. While all the refineries are good, this is generally how you'll want to look at it:

If you're looking for pure offense, your priorities should probably be:
1. Alm
2. Raven
3. Caeda

Most of them are great, Caeda and Marth both have great new weapons, just go for it

try Felicia's plate, really fun :D

Guys, let’s also not forget the Mage slayer Felicia. She’s pretty worth it too. I seldom used her until this refinery for her came out.

...but yeah, i’d Say Alm or Caeda for offensive purposes.

Felicia's Plate drastically improves her damage problem...but I'm not convinced that it needs the effectiveness refinement. Cooldown reduction only against magic is...useful... But I wonder if +SPD or +RES wouldn't be more helpful?