Help: 4-cm send/return settings

I’m using the four cable method and added an FX loop block.
I’m a bit confused with adjusting the I/O “send and return” levels.
How do I determine the settings?

Also, there are send/return levels on the FX Loop block as well. Is this for saving snd/rtn settings per individual preset as opposed to I/O snd/rtn which is global?

Thanx for any help!

The fx loop send and return, mix levels are accessed within the fx loop block parameters. The levels are for what ever you add to the fx loop and mix is for adjusting how much of the fx loop you want to be in your signal chain. Be default, setting are set to max for S/R and mix is 100% etc.