I know a lot of new players or players returning from long hiatus LOVED the 2 Shard cost as it helped them easily get such pretty applicators for themselves, whilst some others complained and preferred it back to 5 Shards.

I personally liked the 2 Shards, but-

How about this:
Shard usage is RNG. It can range to it costing 2 shards up to 5 to move, all based off random chance. So one movement could be 2 shards, your next be 5, then its 4, or 3, and goes on like that.

Or something similar to that, at least!
Some have suggested 2-4 shard RNG.