I actually really wasn’t convinced that this would be a good a idea when it was discussed in the Level 21 before 2021 thread, but I think you did an amazing job, @Marifly! The whole thing with the Tokyo Skytree? I don’t know, it just works for me.
I also would suggest, similar to @kmurgs, that you single the levels 35 and 45 out of the 10 level intervals. That way, when you are on those levels, you actually get the feeling of “stepping outside” the tower for a bit and having reached a milestone greater than just one level or ten levels.