Here's a little suggestion. The RPG Pundit just posted about why Charisma isn't a dump stat. Nothing surprising or disagreeable here, since the suggestions are pretty standard here in Old School Land. But it did spur a tangent thought. There's a slight rift between two groups of old school GMs regarding the reactions of monsters to characters. One group almost never uses reaction rolls outside of negotiations with merchants, hirelings, or other neutral townies. They feel that monster reactions should be based almost entirely on role-playing the creature, and it should almost always be a hostile reaction (the adventurers are invaders, after all) unless the situation is truly remarkable and warrants a different reaction. The other group like to roll for almost every monster that isn't outright mindless. They like the surprise that comes from monsters having an unexpected reaction.
The objection of some GMs to reaction rolls, particularly from the first group, is that it's particularly easy to forget to make that roll. It is kind of an extra step. But if you don't roll, having most reactions be hostile means that encounters are going to be pretty repetitive: meet a new creature, fight it, take its stuff, repeat.
But what I'm thinking is: if you're always going to make at least one reaction roll for almost every creature, that doesn't mean you have to make that roll during play. Do it when you're writing your encounter notes and record the base reaction right there. When the encounter actually occurs, add or subtract Charisma modifiers or situation modifiers to get the actual reaction.
Adventure designers could make the description system neutral. Pretty much every version of D&D and a couple other games like TFT/GURPS breaks down reactions as Bad/Hostile, Neutral, and Good/Friendly, with Very Hostile/Friendly or Extremely Hostile/Friendly at either end. Record the base reaction that way ("The gnome-king will be generally Friendly") and let the GM substitute the lowest score that matches that category, then modify the result to see what the monster's actual reaction is. New and unexpected events may trigger a re-roll on the spot, but otherwise just modify the current score up or down to see how the monster's attitude changes.