We changed the name of that tag for a reason
The internal-consistency tag used to be named "reality-check." The problem is that people were using the tag for what the words "reality" and "check" meant to them and not per the tag's wiki. , 
What the tag expected: To test how consistently someone was using a developed rule or rules. One or more rules were defined and a story-based circumstance using the rules presented. Respondents were expected to answer "yes," meaning the presented circumstance was consistent with the presented rules or "no, because..." if they felt the presented circumstance failed the rules.
What the tag was used for: Do you like this idea? or any one of its thousand variations including "is this realistic?", "is this feasible?", "is this possible?" etc.
Thus, the name of the tag was changed to reflect its original meaning. I made a small and nearly useless effort to remove the tag from historical questions that were following the second bullet — but it's a lot of work.
At this time, we don't have an official way to ask review-my-idea questions
And that's what a "reality check" question really is, "do you like my idea?" It doesn't matter how it's couched, the user is at best looking for people to poke at the idea to see if there are any obvious holes that need to be dealt with before using the idea or, at worst, they're looking for some kind of permission to use the idea (as in, "this isn't stupid, is it?"). Note that there's nothing wrong with the latter, few people can be experts in every field needed to write a good story, it's just not what Stack Exchange is for.
And that's the problem: review-my-idea questions don't fit in Stack Exchange's mold at all. This type of question is intrinsically open-ended and has no hope of a best answer.
Equally intrinsic is the fact that internal-consistency questions are also open-ended with no hope of a best answer. Historically, they were a permitted exception because we're dealing with specific rules and a specific test. In other words, the question was very tightly scoped and served a very specific worldbuilding-process purpose. Nevertheless, the hypocrisy is admitted.
I tried to resolve some of the problem by inviting advice to users about how to ask review-my-idea questions. It was reasonably well accepted (for today... hardly any Meta users today...). But few people other than myself link user questions to Meta posts to help people learn how to use the site. (There's a lot of good stuff in here....)
This goes to underscore how hard it is to name a tag...
For the record, it's really hard to name a tag in a way that can't/won't be abused. 99.9% of the time, a user will use a tag based ONLY on how they interpret the words used in the tag name. "Internal consistency" is working better than "reality check" ever did (wow, that was a mess...), but it's still being abused.
But I'm NOT fond of setting a precedent
What worries me the most about this is the precedent it might establish of re-defining tags to meet the experienced use of the tag. That invalidates every "correct" use of the tag historically. From a practical perspective, that's just trading one kind of confusion for another in the hope that the second will be less painful, which usually means "less effort to moderate."
To use a metaphor, we believe it's easier to plant the grass and wait to see where the walking trails appear, then pour concrete for sidewalks, than it is to build the sidewalks first and forever hound people to use them. I get the argument, I just don't agree with it. The result may be less maintenance, but it's almost always less attractive (at best) or less fundamental to the design of the campus (at worst).
So, no, the internal-consistency tag should not be redefined. To top everything off, you're just re-creating the problem we were trying to solve in the first place at the expense of losing a feature that has been with the Stack since its earliest days.
Shame on us, perhaps, for not remaining better focused on the task of helping people learn how to build worlds. We've fallen into the habit of just helping the OP of the moment solve their individual problem, ignoring the SE expectation of reuse of data. In short, we've fallen into the habit of giving people fish rather than teaching them how to fish.
And the tag has a specific purpose that is wholly independent of the other tags. By definition (literally...) you can't have a science-based answer to an internal-consistency question because the rules and the means of testing the rules must be required for the tag to be valid. Science (or its lack...) has nothing to do with the consistent use of a rule.
OK, so shouldn't we just burn the tag and forbid any and all "review my idea" questions?
That's the only definitive solution, but the effort to do so is horrific. To burn a tag we must disassociate each and every question from the tag and then let SE's garbage collection get around to deleting the tag.
Instead, let's return to teaching people how to fish. Rather than redefine the tag, choose to delete it when it's been inappropriately applied with an admonition in comments to read the tag wiki.
BTW, why was it named "reality-check" in the first place?
Remember that our goal (per the Help Center) is to help people build imaginary worlds. From that perspective, the phrase "reality check" meant "your reality," not the Real World. What time taught us is that the average person (especially young users) treated the word "reality" to mean ONLY "the Real World." This became exacerbated as things like the TV show "The Expanse" and the Real World Question policy turned this site into Physics-Lite where the only reality of interest was the "Real World" despite the utterly nonsensical fantasy of what the OP was trying to do. Thus, it was decided we had to change the tag name to better express the tag's wiki, rather than the wiki to better express the name.
One last thing...
As part of the repair to the various tags related to this post, the reality-check tag was made a synonym of the science-based tag, because when you remove the review-my-idea component of the question, that's what it really is: a reflection of the desire for a science-based answer.