It does exactly what @emory_krall has already been doing! It just calls extrude separately for each selected profile (so no guarantees on performance). 

        var definitionForOp = definition;
        var count = 0;
        const relevantEntityField = definition.bodyType == ToolBodyType.SOLID ? "entities" : "surfaceEntities";
        for (var entity in evaluateQuery(context, definition[relevantEntityField]))
        {
            definitionForOp[relevantEntityField] = entity;
            
            // keep original id for first entity so that manipulators work
            var idForOp = (count == 0) ? id : (id + count);
            count += 1;
            
            extrude(context, idForOp, definitionForOp);
        }

Basically make the user supply the same definition as extrude takes, then apply to each entity separately (with some id finagling).
Some semantic sugar also:
'definition.entities' is the same as 'definition["entities"]'
ternary operator (var a = condition ? this : that): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator

 Hi All!

Thanks for the kind words, glad I could help!  I've pushed a V2 with a very small fix that makes references to the created bodies more stable.

There's also some weirdness with the "entities" box (you may notice all of your selected faces collapsing into one selection called "Missing of sketch X").  This should not be a huge problem as selections/deselections should act as usual in the graphics are.  We are investigating this as it seems like a systematic issue, hopefully it doesn't cause too much inconvenience. 

@mbartlett21

Yup, it's caused by the Id, but if I don't piggyback off the Id in that way, I'd have to do extra work to have the manipulators (or just not have them at all).

Glad to help @paul_bunnell !