Unable to use taskbot in update mode from Roxy controller that uses query-router#4

I am working on a Roxy app that uses the Roxy rewriter. Each rewrite rule uses either the query-router or update-router. I'm trying to use taskbot (which is a very nice library, btw) in a Roxy controller that uses the query-router. I am invoking taskbot:list-segment-process - the one that takes 6 arguments (sequence, batch size, job label, function, map, options). I am passing in OPTIONS-UPDATE for options. My function attempts to insert a document. MarkLogic complains because of an update happening from a query transaction. My assumption was that since taskbot should be executing the function on the task server, the fact that it does an update shouldn't impact the read-only transaction. Have you run into this before with Roxy, and/or have any idea what I'm doing wrong? I'm working around the issue now by doing an xdmp:eval on the function that invokes taskbot so that taskbot is invoked in a separate transaction.