There was one consideration I realized that is, to me, an overriding consideration that stopped me from an already started project of learning link titles.
It is common practice for link text to be the title of the link target. It is, arguably, even more common practice for link text to effectively be some improvised comment or remark about the link target.
The following link capitalization, in terms of "non-verbal communication", is ambiguous as to whether the link text identifies the target's title, or whatever remark or summary the author improvised; it seems to lend itself to reading the link text as an improvised remark written to match the context of the page it appears on:
Xxx x xxxxx xxx x xx xxxxxx xxxxxxxx xxxx xxxxxx x x.
The title case capitalization strips out the ambiguity in the case of repeating a document title, which can be particularly helpful if the document's title does not fit the flow of the sentence to the degree one would often encounter with an "improvised remark" link text:
Xxx x xxxxx Xxx x xx Xxxxxx Xxxxxxxx xxxx xxxxxx x x.
That is why, after doing significant work to start converting all the text of CJSHayward.com from title case to sentence case, I am rolling the transaction back.