Off to look at those
Have you used one? I'm always really safety conscious with wheels - I don't think any of them are perfect - except maybe the Rodipet ones and they're more designed for tanks. But now I've found you can use the silent runner bar attachment plates with other wheels that opens up options.
I've just sent for a 28cm Trixie wheel from Amazon to have as a spare for the playpen as it seems hard to find wheels in stock right now at reasonable prices.