His father's given name Holdlien is a new name to me (as is Hoedlyw).
I need to change the LNAB to include ap - or ab? Does his father's given name begin with a vowel sound?
I'm hoping that someone who speaks Welsh might answer that question and also maybe have an idea of of which spelling would be closer to correct, if either is.
A soundex search came up with Huddyll (which Google translated from the Welsh as "ugly" - so his Dad was Ugly Red :D).
I can almost think Huddyll might have gotten written as Hoedlyw (or vice versa) but I don't see the leap from them to Holdlien, which is how it's spelled in one of the profile's sources (the [Google Book]).* DBE suggestions include a wikidata page for him, citing thepeerage (which cites an e-mail), WeRelate (which cites Bartrum, Elystan Glodrydd 1) and WikiTree. (The [wikidata page] calls him Hoedlyw, as does WeRelate - referencing Bartrum, so I'm leaning toward Hoedlyw.)
* The other source listed is Montgomeryshire Visitations ([vol 1, page 290]), but if either Hoedlyw or Holdlien is on that page, I missed it.