In many cases protocols that use LN micropayments under the board, there can be multiparty escrow schemes that enable users to pay via external channels (including custodial) that allow the purchase of vouchers for service, without the friction of waiting for their own channel to open to get started. It has other sticky issues, like how to automate that process, but I know for sure at least some LN wallets can be controlled using an API, closing the loop.