Should more champions have Off Meta Scalings?

I try to play off meta a lot or at least test stuff out in practice mode, for example my toplane , toplane (with muramana and archangels) and recently i tried magic pen in practice mode, becasue her W does magic damage equal to a percentage of the targets max health (which can increase infinitely) and i just found it annoying that despite being a Spirit, (somewhat magical too) she has no Ap scalings to make use of all the ap from my items.

At least has some ap scalings on his W so you can go magic pen for his Q damage and still get some slight value out of his ap, same with who has an ap scaling on his ult.

Just wondering about it, also i think my kindred build could use some changes.