Bounty of Skemfar is not legal in modern since it's from kaldheim commander, not kaldheim itself. Anyway I would say it's almost always worse than Lead the Stampede and Winding Way.
Then we have a couple of good 4 drops that may be worth considering in Tyvar Kell and Harald Unites the Elves for grindy match ups. They are not synergistic with CoCo, obviously, but with 4 CoCo and 3 of a combination of Tyvar Kell/Harald Unites the Elves we have around 33 and 35 hits off CoCo depending on the amount of lands we play. And 33 hits are more than enough for consistency.
Last but not least we have what I think it's the best of them all: Realmwalker. The fact that it's CMC 3 instead of 4 like other similar options makes it a CoCo hit which is just really important.
All things considered, Kaldheim could make elves somewhat playable in modern again. It's unlikely, but maybe.
Then we have a couple of good 4 drops that may be worth considering in Tyvar Kell and Harald Unites the Elves for grindy match ups. They are not synergistic with CoCo, obviously, but with 4 CoCo and 3 of a combination of Tyvar Kell/Harald Unites the Elves we have around 33 and 35 hits off CoCo depending on the amount of lands we play. And 33 hits are more than enough for consistency.
Last but not least we have what I think it's the best of them all: Realmwalker. The fact that it's CMC 3 instead of 4 like other similar options makes it a CoCo hit which is just really important.
All things considered, Kaldheim could make elves somewhat playable in modern again. It's unlikely, but maybe.