No they haven't, and this was actually a discussion that we'd resolved in the Discord Staff Chat a long while ago. We examined every user there and found that none of them matched the given description of Boundless Inner World. Especially because it's about more than an inner world - it's about having an intelligent being who rules an infinite inner world and provides you strength/power/whatever. We also talked about changing it up to reflect something that might exist in fiction, but the creator DYBAD was against the changes we'd need to make because it would fundamentally alter the power as he intended it. We eventually resolved that it would be better to just make this a Userspace power - that way the idea is preserved since people do like this power, and so that we remain consistent on the wiki's main space.
We just never got around to implementing the change of this to a Userspace power.
There's a huge difference between a Boundless Inner World and an internal persona who has all knowledge. The "world" part of that character is complete fan extrapolation. It's not much of a "world" so much as it is an internal entity with boundless knowledge... which doesn't tick all the boxes.
Originally I actually used Venom as my defense of keeping this power way back when we had this convo in the Staff chat, so I get where you're coming from thinking that. However, part of the power is having a sentience to your inner world. The "sentience" of the Venomverse at the end of that story is just Venom, which is the same intelligence as is outside of it. There isn't a being that is functionally omnipotent within that BIW and that provides the external user power. It DOES provide him power, it's arguably boundless, but it's not sentient, so it fails to tick all the boxes. I went and watched a, like, 30 minute synopsis of the story to research it.
As for the "Are you seriously joking?", no, I'm not. This was an approximately twelve hour conversation about this topic that I am not interested in repeating. We really did comb that user list - none of them counted. It was a nightmare of a day, and frankly even thinking back on that convo stresses me the hell out. It was very stressful.
Hi, speaking as another staff member who also sacrificed her entire sleep schedule for the argument in staff chat here. Venom the End's inner multiverse was determined as insufficient for a truly Boundless Inner World, as the power itself possesses no degree of sentience. The contents may have been sentient, but the world had no sentience (like the Shinra Banshou, which was disqualified due to not necessarily being boundless), which leaves us...with nothing.
Anyways, we're ready to happily answer the questions of other editors about BIW if they come up. It's not a headache for us if they understand our reasoning for this.
Shinrabanshou does fit the power as originally intended near perfectly if the story is to be believed, which makes sense considering said power was almost entirely based on it.
The "sentient pool of infinite power and knowledge" idea is pretty much the definition of the entity, which was hammered from beginning to end in the series, and was the exact reason why everyone was chasing after it. There was no definite proof of said infinity (not really sure how one can prove that) just like there wasn't any proof to the contrary either. So the truth of it is simply uncertain, and it all depends on whether or not we believe the in-universe claims, just like the claim of a character's Omnipotence is rarely ever confirmed beyond reasonable doubt, and listing them as known users or not is a choice of belief.
Still, a call has to be made one way or the other, and seeing the very limited feats displayed during the series (to be fair it was a particularly weak setting where powers barely even existed, and the writer was awfully reluctant to display Shinra's capabilities - reducing the whole show to uttery meaningless drama), it has been decided that Shinrabanshou doesn't fit.
The most crucial point however is that "Boundless Inner World" was never meant to be an actual world but really just a "pool of infinite power and knowledge" (exactly what Shinrabanshou is). And while the idea of world is barely mentioned both in the capabilities and applications, it has apparently become a key characteristic and central focus in the mind of most readers, whose understanding of the power was based more on its name and the associated idea than the actual content of the page.
So on one hand the core user ends up no longer fitting, and on the other this discrepancy cannot be fixed without denaturing the power in the eyes of most readers. So the current situation is a genuine dead-end, leading to the power's removal from the main pages.
Now that it has become a blog, I will work on fixing the discrepancy and refocusing the power on what it was always meant to be, and hope that Shinra will be accepted as a known user of the new version. Otherwise, it will probably become a userspace fanon power allowing edits from other users (we found the trick a couple days ago).