Whonix run Iceweasel with proxy, Tor Service still in background?

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1

I will run Iceweasel (not Torbrowser) through a proxy but I don’t know if whole traffic in the background would still run through tor? So I will change network settings in Iceweasel to run Iceweasel through a proxy. Would the traffic still first go through Tor and then through the proxy or just through the proxy and not through tor anymore?

2
I will run Iceweasel (not Torbrowser) through a proxy but I don't know if whole traffic in the background would still run through tor?
Everything from Whonix-Workstation conceptually always must go though Tor. No way around that.
So I will change network settings in Iceweasel to run Iceweasel through a proxy. Would the traffic still first go through Tor and then through the proxy or just through the proxy and not through tor anymore?
user -> Tor -> proxy -> destination

See also documentation on tunneling stuff: