Store & Forward - what are the requirements for using it, please?

[adingbatponder]

For the simple case of the nodes having firmwear 2.5.7 stable and above. For iOS or Android.

1. Does using Store & Forward require the node providing the Store & Forward (the S&F node) and the client node retrieving missed messages from that S&F node, to each have at least one same private channel set up, with full PSK, in their channel list?

2. If yes, does the order of the channels in either the S&F node or client node matter?

3. I do not use the new app, and use old one e.g. Android 2.4.4 . Does using the the newer updated app influence the answers above?

4. Is a node database reset in both the client and S&F node essential to make the direct messages from the client, that activate the S&F node, function?

5. Is a restart of the Meshtastic app required when adding or changing channels?

Reason for asking now: I want to know if the new public/private key system has made the need for a private channel in common obsolete, or if this is still an absolute requirement for S&F to be used.

Use case / motivation: I need to double-check. I am intending to make a private channel with full PSK, whose PSK is then shared widely in the local mesh, to make the S&F nodes of the local mesh fully accessible to the whole mesh.

I did not find any statement on this in the docs
https://meshtastic.org/docs/configuration/module/store-and-forward-module/
and would really like some hard info for the superb Store & Forward functionality of Meshtastic.

[adingbatponder]

Is there a user guide for Store & Forward?

[ikearat]

His link seems to be what there is available (without filtering a bunch of junk for tiny clues, which I have not done myself :)