I cut my own but I wouldn't if I could buy them. I sometimes make multi-plunge mortises of various widths and of course I have to cut my own for these applications. This has been so since the beginning of loose tenon joinery. But it would sure be nice to have store bought tenons to match a good sampling of widths available with single plunges, especially for the larger bits. This comes up every now and then but it's been a while if any Festool folks are listening.