I don't know anything about minibits/ecash so I'll leave that to others,

but while looking for ways to manage channel liquidity I realized that (in my case at least) going from lightning->on-chain is more expensive than going from lighnting->liquid->on-chain.

The liquid-step also allows me to collect some smaller amounts and later swap those into a single on-chain UTXO

My guess: there is no "best"