Hostapd and wpa-supplicant 2.7 have been in Debian experimental for some time already, with snapshots available since May 2018, and the official release since 3 December 2018. I’ve been using those 2.7 snapshots myself since May, but I do realise my x250 with an Intel Wi-Fi card is probably not the most representative example of hardware wpa-supplicant would often run on, so before I upload 2.7 to unstable, it would be great if more people tested it. So please try to install it from experimental and see if it works for your use cases. In the latest upload, I have enabled a bunch of new upstream features which previously didn’t exist or were still experimental, so it would be great to give them a go.