Okay, I'm going to call this solved. I know it would have been faster to do this if Fetch was able to handle roll Templates that look at the result of a roll, but since it couldn't, I made my own API to just make this one roll. Once I realized that token.get('currentSide') was an API command, the rest fell into place pretty quickly. on('ready',function(){
"use strict";
var handleInput = function(msg) {
if ((msg.content.indexOf("!rollbyface") !== -1 ) && (msg.selected)) {
for (let i = 0; i < msg.selected.length; i++) {
let token = getObj("graphic", msg.selected[i]._id),
token_name = token.get('name') || 'Minion Roll',
speaker = 'player|'+msg.playerid,
diesize = 'd'+(12-token.get('currentSide')*2),
imgs=_.map(token.get('sides').split(/\|/),(i)=>{return i;});
if (imgs.length != 5) {return};
//sendChat(speaker,'&{template:default} {{name='+token_name+'}} {{'+diesize+'=[['+diesize+'cs>13cf<0]]}}');
sendChat(speaker,'&{template:scrpg} {{name='+token_name+'}} {{die1-'+diesize+'=1}} {{r1name='+diesize+' = }} {{roll1=[['+diesize+'cs>13cf<0]]}}');
};
};
};
on('chat:message', handleInput);
});