Hello there. I was tinkering a bit with the pack for a future playthrough, but when using the pack without any changes, every planet except nauvis would be missing a lot of materials even when the frequency of those resources is really high. it seem that rare metals, immersite and se materials do spawn but most BZ and most of the over mods ores don't seem to spawn at all.
I haven't touch any settings and I use the space exploration default map setting at launch.

Known issue with SE. Patches to fix it exist and we are hoping to convince the SE people to merge one of them... eventually.

I did see this yesterday as well! There seem to be plenty of researches on Nauvis. Just for the sake of discussion; how is it to go to new planets with most of the ores not spawning? Is it still fun/useful? Are planets now just to shoot resources since I suppose most products cannot be made on new planets.

As someone with a 31 days save (that is 31 days running, not AFK), I have chosen to make Nauvis the hub where most things are made. Most basic things can be made everywhere, and those which can't be made indigenously, but are better made on location, can be made by sending the missing materials via delivery cannon or rocket.

I've got a mod out now that uses a workaround to spawn the other resources. (Only on newly generated surfaces, but that includes deleting and recreating them.)

https://mods.factorio.com/mod/se_mod_resource_spawner

I'm fairly confident it won't break anything, but I still recommend saving before looking at new surfaces just in case.