Highly endorsed! I favor the 120mm (that's 4-11/16" to you Canadians ) square deep box with a 2-gang mud ring or domed cover. (The 4x4" box is a mistake, it's way too crammed by the time you get dual DFCI receptacles + wires all in there. Make life easy on yourself.)What I'm saying is if you place an AFCI outlet beside the panel on a short conduit nipple it can save you the aggravation and expense of running metallic wiring to the first planned outlet.
You can even install a stack of boxes maybe 1/4" apart with EMT short connectors - just far enough apart the lids don't interfere. (made that mistake lol). Note that very short EMT pipes do not have a 4-circuit limit, so you only face wire fill limits (3/4" EMT: twenty-two #14 wires or sixteen #12 wires). And EMT handles ground for you, so don't need those wires!
In Canada you're not allowed to splice inside a service panel, so you'd have to re-route the circuit to start at the junction box where the AFCI deadfront or receptacle would be. Terminate the ground at the metal box ground screw(s) and let the EMT take it from there.