Best ways to 'join' data with helpers

1

Suppose I’m subscribed to 1000 items and 1000 itemRefs, and I have this code:

// ItemRefList Blaze component 
Template.ItemRefList.helpers({
    itemRefs(){
        return ItemRefs.find();
    }
});

<template name='ItemRefList'> 
    {{#each itemRef in itemRefs}} {{> Item itemId=itemRef.itemId }} {{/each}}
</template>

And this:

// Item Blaze component
Template.Item.helpers({
    item(){
        return Items.findOne(Template.instance().data.itemId);
    }
});

<template name='Item'> 
    {{item.prop1}}{{item.prop2}}{{item.prop3}}{{item.prop4}}{{item.prop5}}
    {{item.prop6}}{{item.prop7}}{{item.prop8}}{{item.prop9}}{{item.prop10}}
</template>

Now each time I request a prop on item the helper is fired and the minimongo needs to query the collection.

Would the following be more performant?

Template.Item.onCreated(function(){
    var template = this;
	
    template.autorun(()=>{
        template.reactiveItem = new ReactiveVar(Items.findOne(template.data.itemId));
    });
});

Template.Item.helpers({
    item(){
        return Template.instance().reactiveItem.get();
    }
});

Any best practices for situations like this?

2 
<template name='Item'> 
    {{with item}}
      {{prop1}}
      {{prop2}}
    {{/with}}
</template>
3

Thanks, that seems to work. Means a 10-20% speed increase for a page in my app! (5s->4s page load)