I would like to use BRC-20 for completely uncensored communication.
Then why don't you run your own Nostr or Matrix server?
That is alongside the second layer scaling solution and as a complementary improvement because something like LN can not solve much alone.
Well, if the problem is that on-chain peg-in transactions are not sufficient to bring all people inside LN, then there are other solutions. One of them is to put channel-opening transactions to the off-chain world:
https://delvingbitcoin.org/t/can-game-theory-secure-scaling/797/1 And another is of course CoinPool, or other similar proposals, to switch from 2-of-2 multisig into N-of-N multisig:
https://coinpool.dev/Opening LN channel from sidechain sounds interesting. But on other hand, it'll require some party use LN software which monitor activity on that sidechain. And in practice, both party could just create the transaction on sidechain itself since sidechain usually offer lower TX fee.