So, Ultimator (Known as "Lambdawg" on dicord, I think you met him/her) recently showed me your refute to tier 1 homestuck. Here's my response to it.
So, if IIRC, your problems with tier 1 homestuck is
1. String Theory being too vague
2. Homestuck and Problem sleuth being hardly connected.
Here's my response
Regarding the String Theory
Because this happened, the trend of "Tier 1 Homestuck" came to life. However, there is more supporting Homestuck running on string theory: This.
It may not seem like much at first, but you see the GPI sowing the Universe back together with a sowing machine. What does this imply? GPI sowing the Universe back together with something: Strings. According to string theory, it's where the universe is made up of strings. So, sowing the universe back together with Strings supports string theory. Thus, String theory in MSPA has support.
Regarding the Connection between Problem and Homestuck
You claimed that Homestuck and Problem Slueth's connection is too weak. However, this is not true. See this and this. A literal creature seen in Problem Slueth is seen in a newspaper in a newspaper in homestuck. Not only that, but you are forgetting someone:
Hm, alright, I guess Homestuck x Problem Sleuth makes a bit more sense now.
Nonetheless, I don't know how to interpret that sewing the universe thing. It's still a bit vague imo; to me, a realm name plus a single comic relief act (no pun intended) of a character sewing a universe is a bit too vague to instantly assume String Theory exists for the verse.