There's no other L2 than LN.
All the rest are SOMETHING ELSE but not L2.

DarthCoin

I intentionally used the vague term "L2" to avoid limiting it to LN here.

If you use a shared UTXO like ARK, you will need a deposit, but you won't have to worry about unintentional forced channel closures. Or, although it does not follow the principle of unilateral exit, if you use a custody like ecash, you won't even need a deposit to L2.

However, I agree that the point that L1 and L2 are a set and therefore problematic is very valid.

bitcoin

What problems would there be if L1 were filled by something other than BTC tx?

teatwo

I intentionally used the vague term "L2" to avoid limiting it to LN here. 

If you use a shared UTXO like ARK, you will need a deposit, but you won't have to worry about unintentional forced channel closures. Or, although it does not follow the principle of unilateral exit, if you use a custody like ecash, you won't even need a deposit to L2.

However, I agree that the point that L1 and L2 are a set and therefore problematic is very valid.
