Hi all, I’ve been building LeagueMaker (https://leaguemakerapp.com), a free web tool for running tournaments, and it now supports McMahon: initial scores from kyu/dan ranks with configurable bands, automatic pairings, Buchholz/SOS-style tiebreakers, and live standings you can share with a link. No install, works on a phone or tablet at the venue.
I’m the developer, and I’d honestly rather get picked apart by people who actually run Go tournaments than keep guessing what organisers need. If you try it with a real or test event and something is wrong or missing (bar placement, handicap handling, EGD export…), tell me and I’ll put it on the list. Guide: https://leaguemakerapp.com/p/create-go-tournament