EDIT: I forgot to mention this in the first half: these were things that I noticed while making my most recent design, which I only had enough excitement to finish because of Christian's comment on this post, so thanks again for the fun :D and yay for the first braille favorite!
First, some bugs. In a loop that says repeat [n] times, subtracting variables inside the [n] will cause the page to freeze when the program is run (in this case, it was guess-random). Any number of constant expressions with a single variable, even one defined as [guess-random] will still work. There's a few less dangerous ones with count from  to  with [n] where n is a variable equal to zero and the compiler doesn't catch it.
Clicking reset when the program is on pause on will usually start the program from the top AND the second object where it left off simultaneously. I haven't found a way to make this useful when they both collide on the same object.
Preview images often fail to load, but I think it helps when the design is exported as a part. This often fails, however, or hangs up on STLs and downloads multiple all at once. Gallery images and/or designated alternative text would be a good workaround for this, though the gallery still fails to process .gif files exported from CodeBlocks.
Just a PSA: I noticed that designs will process much faster if you pause before intense steps (and after grouping). The animation I made would stop freezing only if I waited a minute before pressing play on the last step. Perhaps we'd benefit from a notification saying that a pause step is recommended 🤔
I also noticed the four-sided die was rolling a lot of threes. It's not a bad seed because the sequences are different, and here are some very non-uniform numbers I found:
Between 0 and 8 (n=64)
Between 0 and 3 (n=30)
Between 1 and 3 (n=30)
and honestly idc none need fixing as much as buttons without labels in HTML ^_^ thanks!