Interesting question, @tjv. I just took a peek at the Monthly Analysis template and there is a lot going on there. It’s kind of an intricately wired machine… and as @heather says, it was built to work with the Foundation template.
A spreadsheet ninja 
, could pull this off but a better bet may be having a look at our Savings Budget (Prototype). It is a refresh on the envelope budget you are using built to be more performant and more compatible with the rest of our templates and workflows. It’s not quite production ready but you can make a test sheet and take it for a spin 
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@heather and I are hosting a webinar on Thursday and we will demonstrate it.