Cause for request

Tag #forge:fuel commonly used so a lot different fluids tagged like this. But not every fluid shoud be used as rocket fuel.

Request details

New tag (for example #forge:fuel/no_rocket_use) can be added. Fluids tagged like this can't be used in fuel loader.
Or this feature can be adde through mod config. Or even kubeJS support can be added.

But in my opinion tag solution is best.

PS: You can't just remove fluid from #forge:fuel tag becouse this can break other mods

You can do that already modifying 'tier_N_rocket_fuel' fluid tags.
https://github.com/terrarium-earth/Ad-Astra/tree/1.20.1/common/src/main/generated/resources/data/ad_astra/tags/fluids

Ad-Astra/common/src/main/generated/resources/data/ad_astra/tags/fluids/tier_1_rocket_fuel.json

{
  "values": [
    "#ad_astra:fuel"
  ]
}

Try remove '#ad_astra:fuel' element and customize.