Basically, yes. More specifically, the default BunPro Path is intended to follow such an ordering. Therefore, if you’re following the BunPro Path and you find something out of order, it’s fair to report that as a potential issue.
The other Paths, such as the Genki or Tae Kim paths, because they may follow somewhat different orderings based on their source materials, may be somewhat ‘out of order’ in some cases, though the BunPro team have apparently put in a lot of effort to smooth them out as well, but may not really be possible to make all the paths perfectly ‘in order’.
As for adding grammar points in whatever order, you are definitely free to do that. I’ve done that in some cases.
However, you may run into some difficulties if you end up adding ‘more advanced’ grammar points that will likely use ‘less advanced’ grammar points you haven’t come across yet.
When this has happened to me, I usually looked up the new grammar I had ‘skipped’ and also added it to my lessons. In some cases, this ended up with me ‘biting off more than I could chew’, and after taking a break from BunPro for a while, when I returned, I found that I had a lot of difficulty with a lot of the ‘mixed level’ grammar points I had added.
Along with several other unrelated reasons, I ended up resetting my BP progress and started back with the BunPro path from the very beginning again, and now I have been mostly following the BP path with only a few exceptions here and there. For instance, I’ve also added early grammar points from some of the beginner paths like the Genki path (I had previously studied the Genki I book, so I feel confident with those), the Marugoto path, and some scattered grammar points here and there. But I try not to bite off too much. If I find that I’m starting to have difficulty with some of the higher-level grammar points, then I basically focus on just continuing to do my reviews, but stick to just regular BunPro path lessons for a while, until the higher-level grammar points no longer trip me up. Then maybe I’ll venture forth and add a couple more again. But I take it more slow-and-steady these days than before, and I find it much more ‘comfortable’ this way.
So, try it out, but be careful about possibly biting off more than you can chew. If things get too hairy, just slow down and go back to the default BunPro path for a while until your grammar skillz catch up closer to where your reading material is at. If things get way too crazy, you can always either reset, or just remove some of the more-difficult grammar points out of your reviews (each grammar point has a button to remove it on its page).