Squid3 Proxy Configuration Tips?

In our environment, we need to use a proxy for servers that are on non-internet-routable networks, back up to public cloud providers and interact with the MSP console access.

I would very much appreciate any tips that folks might have regarding use of certain Squid proxy server configuration options. For example, how does Keep_Alive benefit backups? Any gotchyas that we should consider when setting up this proxy?

Thanks for posting!
Hope that some of our customers who use proxies will share their experience regarding that.