The repository is now open, here it is: https://gitlab.com/peakd/hive-open-polls/-/tree/standalone (the standalone branch is where the most recent work is happening). It is currently functional. It's built as a HAF app which can run on a HAF server, or it can run on its own without needing HAF or hived.
It not only indexes but also implements all the logic of the protocol, checks the validity of the poll to ensure it conforms to the protocol, allows post title and body updates but no changes to the poll question and choices, allows voting and changes/removal of votes but only up until the poll's end time (if specified), calculates the interpretation of results, checks for filters and filters out the accounts that don't meet the filter criteria, and so on. There are various pieces of logic which will grow as the protocol expands and more poll types are enabled (multi-choice, etc.).
The server requirements are extremely minimal, it is a super small app. 1GB of RAM would be plenty, and the app's docker image is something like 600MB.
Would you like to give it a test run?