Had a good haul, should i save more and use them all on this legendary banner?

I saved up to 276 orbs, which is I think the most orbs I've had since I tried for the world of radiance banner. I'm f2p and seeing all these amazing units out and so many banners, I knew I had to summon. I was sold when I saw L!Ephraim but sadly I have still not gotten him yet. I'm not mad however because I got amazing units on this banner (not as many as I would have hoped but it's still good):
x2 Mia (neutral IVs, -spd +res)
Brave Ike (+hp -spd)
Summer Leo (-atk +res)
Summer Gaius (-atk +res) (my pity breaker :/)
Grima (-spd +res)
Summer Corrin (-hp +atk)
x2 4* Soleil (a unit I've wanted for a long time but never got)
I only have 8 orbs now (spent a few trying to go for LA!Hector but luck was not on my side). Should I use the new orbs we'll be getting in March to continue to summon on the legendary banner for L!Ephraim?