Kazakhstan, Kyrgyzstan, Uzbekistan and Tajikistan. Four countries, one QR code, and nothing to swap at a border. The surprise for most buyers is Tajikistan, because plenty of regional plans stop at three countries and never say so on the buy button.
Turkmenistan is the country people ask about, and the answer is no. The state runs its network on its own terms and mainstream travel eSIMs do not reach it. If Ashgabat or the Darvaza gas crater is on your route, plan to be offline there and tell someone at home first. No provider is holding out on you.
Central Asia in a brochure often stretches to the Caucasus. Here it does not. Azerbaijan, Georgia, Armenia, Mongolia, Russia, China and Afghanistan all sit outside this plan. If your trip includes any of them, treat that leg as a separate purchase rather than assuming the map is bigger than it is.