Another verified place to spend sats during your BTC Prague visit: Hadog
https://btcmap.org/merchant/node:4906256922
Delicious food (posh burgers), fast service, even faster payments! Close to the conference too.
More places: https://iris.to/note1d76e0h8rq9r32z5pmavn99ddyz4ejj8f69z6krfxns07d79c5lksewlwxn