I support the idea. But in the absence of this feature, you can use
Loyce.club. (Only if you have posted after July 21, 2019)
For example, below is one of the topics you have posted in. You can use this link and then use CTRL+F
http://loyce.club/archive/topics/525/5255379.htmlAlso, in the thread you are referring to in the OP, you can click on "all" button, see all posts in one page and then simply use CTRL+F.
In the case a thread is so long and "all" button is not available, you can use the tool created by LoyceV.
(Visit the link below.)"Show All" on long topicsThis is good way to do it but I guess it's the same thing as OP. Only in your case you have to go to LoyceV's archives and then search it there. We could use the OP's idea so that we don't have to divert to other sites and then do it from there.
However, one can also easily go to their Post history and checkout most recent posts. It would take hardly few minutes to run through 10 pages X 20 posts = 200 posts.
I believe you won't be needing any older posts than that.
Just my input. But the ideas good too.