obsidian would hold 8 buckets? 2x stone crucible
iron would hold 16 buckets? 4x stone crucible
diamond would hold 32 buckets? 8x stone crucible
emerald would hold 64 buckets? 16x stone crucible

just a cool idea

I am unlikely to add this feature as its utility is very low since most players just pipe directly into some giant fluid storage block; if someone wants to make an addon which adds these and wants me to add a few hooks to make easier I would be open to that.