Signposts and Pointers
I think it's useful to split up some terms here, because there are two very different situations you're gonna run into. I'll acknowledge that we use signpost kinda loosely, and I'm not really trying to change that. I'm here adopting the term pointer, because that's the term I usually use when explaining the usefulness of a dupe-closed question to (new) users. And much of that rationale applies here.
Having a question which asks via the actual language someone used point to a question is useful, as others who search via the same terms will find the pointer and be directed to where their answer is. Do note that readers who are not logged in will be automatically redirected. Normally we expect the user posting that to not have found the dupe target, but in a nigh exact parallel to self-answering, that's not a requirement.
Ok, let's talk about (what at least I understand as) signposts: that's questions which are asked to serve as the dupe target for many other questions. The example that springs to mind is for spellcasting and multiclassing in D&D 5e and the thing to note is the preceding meta discussion. And the list of other questions that this question seemed to try to cover really implied this. Except there was no meta, and the dupe closure the wrong way. Though if you'd gone ahead and closed all those as a dupe of yours you'd have gotten a very different reaction.)
Onto dissecting the specific question you posted. The list of questions on the topic read like it's the start of a meta discussion not a mainsite question. (Basically it reads like the meta discussion for making a signpost, as discussed above.) And the last paragraph reads more a comment on tag meaning expectations, which is possibly staring too close at our tag system. I decline to delver deeper into that, but I'll say I'd accept it as a reason for the dupe to exist. What seems missing, and this is kinda a self-answer phenomenon, is why you're asking a question. Not why you're posting it despite it being a dupe, but why you where searching in the first place. Dupe and self-answers are expected to be real questions too, and the only thing which forms the question itself in that post is "each of this things takes an action of some kind described under actions in the combat rules, so can you do it outside of combat? Or can you only use them in combat?". The actual details and needs are what makes a good question, regardless of who asked, answered, or dupemarked it.
Switching gears a little bit, when self-answering (and dupe marking is a kind of answer) it is fruitful to avoid the optics of rep-farming. Asking low quality questions they can answer themselves is what someone who's trying to generate internet points for themselves would do. So, whether consciously or subconsciously, some questions are gonna get hit by that reaction. Now obviously you're not doing that, but you'll want to avoid (accidentally) looking like it. (And no, you don't need to make it a CW to do so.)
To summarize, yes it's ok to post pointer when you had a need. When doing so, make sure the question would be high quality enough to stand on its own (ie. if weren't closed and there wasn't other related questions). Explaining the closure (so it doesn't look weird) is a nice bonus, and realistically explaining first might be nicer than getting questioned afterwards.
As a footnote: I don't disagree with the title update on the target, I assume slashes can throw off (simpler) search functions.
And a second footnote: The meta discussion isn't directly applicable as it's asking about the dupe closure the other way, and new question is/was non-dupe but later off-topic.