Wow, it's your 5th lesson already! Here is your new list:
1. heeling: make the "glued to the leg" exercise more like heeling: still do different kind of turns, but also some normal forward walking in different speeds (slow, normal, fast) to teach them to adjust and keep the right position in every situation
2. figure 8 backward: tell the dog to go into heel position and start spinning as we were doing on the target, then very suddenly stop and step back with the other leg (if the dog is at left side - with right leg), you can also make a gesture with left hand to try to get them to keep circling below the heeling position, eventually all the way around your leg, so that they come backwards between your legs back into front position. If the dog insists on staying in heel position, you can help with the hand a little bit, lure his head out (left for 90 degrees if the dog is on left side) and say back to have them back up in your direction. Step back with the other leg enough to have them back up between your legs. Reward and tell them to heel on the other side (right) and repeat the process. As soon as you get some smoothness with that, stop rewarding for coming in between, always first tell them to come to the other leg and reward at your side in order to avoid having them back up too far - they need to stay very close to your legs all the time.
You can see the steps at 2:51 of this video:
3. skateboarding: try to find a skateboard (kids department) and reward for making it move with front feet. Don't reward 4on, but 2 or 3, the criteria is they make a skateboard move.
4. cik&cap: find a table leg, dog-food container, traffic cone or similar and shape the dog to go around it - first just a step, then two or three circles, both directions (you can reward both right from the start if you are getting it - if not, start with just one, but then on one session, don't reward that direction anymore but wait for the other)
5. fade the object for side legs: if the dog is already heaving both legs up at the same time, click&reward that before he even touches the object, so that he understands the idea is picking them up, not touching something. At the same time, try changing objects as much as possible. Going to vertical objects shouldn't be too difficult, then go to "empty" objects like a chair that looks like an object, but doesn't really offer much support, so at this point, the dog is already free-standing, the object is just there for mental support. Next step in table leg and then you don't need an object anymore. For free handstand, you go through the same process, only that it takes longer as it's physically more demanding - you can start working on it, but do not rush it, especially not with young puppies!
6. don't forget on recalls and playing, stays with distractions (you can combine it all in a really fun game), try the hug on a plastic bottle or something similar that is light enough for the dog to hold it and have them hold it independently, add more steps to backing up from you, tape the 4in the bowl trick again so that I can see to what size you managed to get: the smaller the better!
And most importantly: have fun!