Mt. Magnus had no materials; it was just Central Aelio (Monotite), South Aelio (Dualomite) and North Aelio (Trinite), which all happen to be exploration sectors. If that's a consistent aspect of the exploration/combat distinction then only West Aelio and Halphia Lake will have materials, while Vanford Laboratory and Resol Forest as combat sectors would not.
North Aelio (Trinite) suffered primarily because it was small and didn't have many Trinite locations, and wasn't helped by some people not starting to gather Trinite until almost halfway through CBT which really ate into its already short respawn time. With more time and hopefully taking up some of the space to the west of the bordered-off area on the map, it won't really be a bottleneck for the few third-tier potentials you'll want to unlock unless potential costs are higher in the full game or these materials have other purposes.
It's possible 4★ equipment might have different potential unlocking costs as well, like perhaps starting at Dualomite and needing a fourth-tier material in one of the new exploration sectors. But that would be getting a bit further afield with speculation; the important thing is with weeks of respawning rather than two days, we'll have access to substantially more of those materials already and to anyone who doesn't mind spending a few minutes collecting them all those volumes of those items in the Rappy Dash pack are basically pointless and accomplish nothing other than inflating the pack's price.