I'll like to suggest Drain Blocks being able to actively pick up in world source blocks of any liquid or pull from tanks that are next to it's big holed side. Ideally with support for mods like Aqueducts and Streams. This would provide some good immersive automatisation alternatives for packs focused around hardcore water mechanics.

Example of feature utility to get water from aqueducts to replenish a trough,

Alternatively to this and much better suggestion, the faucet block could be able to stand on its own even if no tank is connected directly to it. In the picture above water blocks from aqueducts act as actual tanks that can transfer water but

a) Pyrotech faucets can't face non solid blocks
b) The faucet would look disjointed in this case

Proposed solutions:
a) Faucets can stand on their own and, if possible, draw a full block model behind them that covers special cases like aqueducts
b) Drain block ability to drain from water source blocks/other tanks to a faucet on the front