The new booking system is much more stable than the old one, most people booking directly now are not having the passport mismatch or disappearing ticket issues that happened during the transition, just make sure the name you enter matches your passport exactly and download the PDF immediately after purchase instead of relying on retrieving it later. Tickets for the following year usually start appearing in batches toward the end of the current year and then continue to open month by month, so keep checking because they do not always release everything at once, and even in February entries can still sell out since daily visitor caps are strict regardless of season. Circuit 2 is the classic and most complete route, so it is the best choice if this is your first visit, while adding 3B the same day is only realistic if you are comfortable with a long day, have an early entry time, and are already acclimatized to the altitude, otherwise it can feel rushed and you lose time just enjoying the site, so many travelers prefer doing one circuit well instead of stacking them.