As always it dependent on your gold and resource situation. Are there other characters that you need to build up? I personally just settle if 2/3 of the obelisk procs are fine otherwise I end up using tons of gold and obelisks just searching for the "perfect" one. You have the two most important ones for elsa imo i would just stick with it.

Having a level 24+ alliance is key imo. People have been clamoring about def pen but really SCD is still king, especially in SL, where you need to chain skills to keep people locked down. Its just not talked about as much because most veterans have SCD maxed or near maxed and assume others have it maxed too. If you cant find a good alliance I would definitely go for SCD on G4. For example, Loki isnt nearly as good without SCD maxed to keep her in her bubble.

Who says you cant do both? You actually should start building your roster for SL asap. If you wait to get a good alliance to start building your SL roster its going to take forever. IMO most alliances lvl 24+ require X amount of AB points per week anyways so you might as well get characters who can clear AB and SL anyways.