LN is a two transaction off chain centralized ledger. You and your buddy control the transactions but unless you have a LN node you are at the hands of the node operators doing it. Since it's off chain it's not doing all the proof of work complex math to keep track of transactions.
I wouldn't buy into the LN concept it's not bitcoin, sure it has two spots on the main bitcoin chain, but the rest is off chain and not bitcoin.
It's a PR move to give people hope that bitcoin can scale, it cannot scale, it's a toy crypto project when you really understand the needs of big data to scale to a global currency level.
It's why TPTB that control Bitcoin (1% of wallets control 99% of bitcoin wealth) are letting the bs that LN is the answer to scaling of Bitcoin.
There's so many better crypto projects around today, I wouldn't even consider Bitcoin today for investing in.
I called the top at 19K for my investors that pay me alot to make calls. I said it would be 10K very soon and it was in days.
Now I'm calling $5K for new floor on Bitcoin, serious investors know the coin is broken and LN is not the fix.
So the answers are you are at the mercy of the node operators and each channel exists only for that set amount since the total amount of the channel is locked into the main blockchain and as such it is immutable and cannot be altered.
So you got your two answers from a guy that has been doing crypto for think tanks for 5 decades since when I was a young kid I was theorizing 6 dimensional math equations for AI computers that don't even exist yet.
When they are created in this level of awareness they will be able to create this illusion easily.
Hologram Universe Theory that's my theory and it was theorized over 40 years ago when I was 16 in a think tank.
https://holographicuniverses.com
You're welcome.