Can I apply for a single entry TR visa in Laos at Vientiane or Savannakhet?

The user is inquiring about the possibility of applying for a single entry TR visa in Laos after applying for a second visa exemption. They ask about the preferred location between Vientiane and Savannakhet for this application. A commenter notes that Vientiane often requires an appointment which can be booked out for over a month, whereas Savannakhet does not require an appointment.