I have homemade 8 frame boxes following the standard Dadant 8 frame dimensions. I find 9 frames fit snugly. So on new brood boxes I squeeze nine frames in. After foundation is fully drawn I pull a frame and leave things loose.
I tried going for 8 in new undrawn brood, and just got a mess. I spaced frames away from the side, but a new swarm built wild bur comb there. The swarm had been hived in the middle frames with foundation, but migrated to the side after I placed them. (New swarms are eager to build natural comb and hardly need or want foundation).
Moving 8 frame bodies, the frame tends to slip and get diagonal because of the extra space. I have ended up with wild comb bridging the gap, if I haven't opened the boxes and carefully reset the frames. (never spent money on those spacing metal pieces).
After everything is drawn deep, I will pull a frame and go with 8. Propolis will help keep the spacing even during moves.