Adding an item short name to the OptionalBlueprints list for a ruleset will allow skipping that blueprint. This is explained in the Configuration section of the plugin documentation, which you can find by searching the documentation for the word "skip".
I've gone ahead and determined the item short names for the blueprints between Salvaged Axe (axe.salvaged) and Flamethrower (flamethrower). Simply add the below content to the player ruleset to allow those blueprints to be skipped.
"OptionalBlueprints": [
"ammo.shotgun",
"shotgun.pump",
"trap.landmine",
"pistol.semiauto",
"grenade.f1",
"pistol.python"
]
If you also want to disallow those blueprints, then you can do that to by adding the following to the ruleset.
"DisallowedBlueprints": [
"ammo.shotgun",
"shotgun.pump",
"trap.landmine",
"pistol.semiauto",
"grenade.f1",
"pistol.python"
]
The full config would look something like this:
{
"ResearchCosts": {},
"BlueprintRulesets": [
{
"Name": "allowall",
"OptionalBlueprints": [],
"DisallowedBlueprints": [],
"BlueprintsWithNoPrerequisites": []
},
{
"Name": "ruleset1",
"OptionalBlueprints": [
"ammo.shotgun",
"shotgun.pump",
"trap.landmine",
"pistol.semiauto",
"grenade.f1",
"pistol.python"
],
"DisallowedBlueprints": [
"ammo.shotgun",
"shotgun.pump",
"trap.landmine",
"pistol.semiauto",
"grenade.f1",
"pistol.python"
],
"BlueprintsWithNoPrerequisites": []
}
]
}