In reply to lcon:
I did it in June 22 and conditions were perfect: firm snow on the glacier, no exposed ice, small bergschrund. Approach shoes with microspikes were fine.
I get the impression that by August the glacier is generally bare ice requiring crampons, and the 'schrund is usually a horror. The combination of that and Bavarian school holidays makes it very much a place to avoid.
The Höllental hut website has very detailed and helpful reports on current conditions during the season (although currently closed). https://www.alpenverein-muenchen-oberland.de/huetten/alpenvereinshuetten/ho...