If you already have a few channels on Phoenix you can also close all and send them to an onchain address 

totally agree with you and that's what i do as well. 
looking forward to better times when most people realize that sats on LN are not "trapped or locked", but instead are freed into the network with low fees and instant transactions!

Tony

I encourage Bitcoiners with LN wallets to do this instead:

bitcoin

Best ways to convert LN sats to onchain BTC?

(apologies for not answer the question) 

I encourage Bitcoiners with LN wallets to do this instead: 
- put your sats to use by buying from Bitcoin merchants/businesses (contribute to circular economy) 
- Educate nocoiners & part of the process is to have them download an LN wallet and you send sats to them 