Barrett, Berio, Ferneyhough, Finnissy, Hinton, Lachenmann, Messiaen, Nancarrow, Scelsi, Sorabji, Xenakis................
Enough plinks there for an entire conference.
But it's entirely unclear what would be discussed at such a conference because, yet again, you omit to define what would presumably be its subject matter, namely "plinks" and their providers. Your arbitrarily chosen alphabetical list of 11 composers does nothing to define it; indeed, it doesn't define anything. Not only that, it doesn't tell us anything at all beyond your ability to make an arbitrary list of composers active during the last century. These composers' dates of birth range across 67 years, from 1892 to 1959. They come from a variety of national backgrounds, being respectively Welsh, Italian, English, English, Scottish, German, French, American, Italian, Parsi/English and Greek. Five of them are still active and the other six have died. More importantly, though, the music of each is very different from that of the others - and these differences are far grater than any that you could name from the 19th century.
Trying to read between the lines of your "plinkered" vision here, the only characteristic that I can deduce from what you might mean by a "plinker" is some who composes atonal music and, if I am correct about that, the appearance of my own name on your list is wholly inappropriate, since I have written none at all other than a handful of very early and long since discarded pieces.
But the most dubious aspect of your non-argument here is not even any of that but the notion of valuing or otherwise favouring a pianist solely, or at least principally, on the grounds of the repertoire than he/she performs - and even Jonathan Powell, who has indeed played the work of most of the composers on your list, also plays the music of many others to whose names I have already drawn attention. If favouring a pianist on the grounds of his/her chosen repertoire is to be a guiding priority for you, would that not then oblige you to deprecate Yonty Solomon (OK, he is sadly no longer a living pianist) on the grounds that he played so much Schumann so often?
Best,
Alistair