There is no way to customize post notice but if it's really needed in future, then we can ask the Stack Exchange team for support. But for now I didn't encounter such a need.
Anyway the meta post you linked also answers your question.
Notices available for Questions & Answers:
citation needed
Some of the information contained in this post requires additional references. Please edit to add citations to reliable sources that support the assertions made here. Unsourced material may be disputed or deleted.
Most commonly used here on the main site (Hinduism.SE) when user doesn't mention any scriptures in support of the answer.
current event
Post is related to a rapidly changing event.
I think it's not used here yet or at least I didn't encounter it.
insufficient explanation
We're looking for long answers that provide some explanation and context. Don't just give a one-line answer; explain why your answer is right, ideally with citations. Answers that don't include explanations may be removed.
Second most commonly used one, when the answer has the potential but lacks details.
Then there are protect, locked and bounty notices.
'Protected' used to protect a question from unwanted answers, sometimes few questions (especially the HNQ ones) attract off-site users too and they present comment like answers and sometimes it happens internally on the site too, 'protect' will restrict new users from answering. It can be added or removed by moderators. Click this tool (available to 2K+ users only) to see all currently protected questions.
'Locked' is used to stop any action on certain post, for various reasons listed below:
Content dispute
This post has been locked while disputes about its content are being resolved. For more info visit meta.
Off-topic comments
This post has been locked due to the high amount of off-topic comments generated. For extended discussions, please use chat.
Historical significance
This question exists because it has historical significance, but it is not considered a good, on-topic question for this site, so please do not use it as evidence that you can ask similar questions here. This question and its answers are frozen and cannot be changed. More info: help center.
Wiki Answer
This question's answers are a collaborative effort: if you see something that can be improved, just edit the answer to improve it! No additional answers can be added here
'Locked' can be removed later or can be added with a timer to remove after a set time.
Bounty notice can be checked by any user who can award bounty.
