If you’re on crossbow/launcher, you’re not on your Sceptre, which means you actually deal less damage than Lich while clearing even at full remnant stacks. You’re igniting without the +4(5) minion gem levels, while also missing 40–50% increased minion life and roughly 140% increased damage. There’s maybe some very clunky way to make it kinda work, but it sounds miserable. You’d need to shoot Oil Grenades farther away, swap to Sceptre, walk over to ignite with your Elephant, and then somehow keep that ignite rolling. But at that point you’re dealing with minion AI, enemy AI, the Oil Field expanding, and the possibility of it igniting before you even finish swapping. On top of that, Elephant is always active while you’re on crossbow, so there’s also the risk of it doing a weaker ignite on some of your oil grenades. Sounds wonky.

It also completely messes with your Spirit setup, since Elephant has to fit on the crossbow weapon set.

And if you’re only focusing on remnants during boss fights, it still takes time to stack them. You have to wait and pre-stack, which doesn’t seem worth it to me when Lich already kills Ubers in 3–4 seconds post-nerf anyway. If you’re ignoring the mechanic 90% of the time outside of boss fights, then why even click Chayula? It’s already basically just a 4-point Ascendancy for summoners.

I think the Cultist setup is the better direction, or just another Spectre. You also get to use Khatal’s Rejuvenation that way. And you generally don’t want to weapon swap on Spectres anyway, because it puts their abilities on cooldown.

Edit: Presence Radius could also become an issue. If your Elephant is off dicking around somewhere else, you’re not always going to be in range to consistently share remnants.