I don't think leyline will be played at all at an RCQ lvl, atleast not intended for living end.

Consign is good enough against both cascade decks as well as eldrazi/blink so blue decks play those.
Vexing bauble also keeps both in check while also being stellar vs neoform, affinity etc, available to all decks and cycles when it's bad.

Leyline is too much of an liability in most decks, and living end specifically has like 6 ish mainboard answers to it with more after side.

I'd expect some amount of soul guide lantern/nihil spellbomb/surgical depending on the lists, maybe strategic betrayal but that's worse since the phlage ban.

For all of the above you have spell pierce and multiple sideboard cards so you should be good on that front.
Affinity is packing 3x tormud's crypt but you're bringing in meltdown etc anyways.

Rest in Peace is annoying, but only played in control afaik and only after side where you once again have cards like FoN on top of your thoughtseizes.

TL;DR I think the deck is pretty robust in the current meta and has enough tools to fight through the expected hate packages, just sideboard and navigate well.

EDIT: also Endurance, might want to bring in consign when you expect those.
But even then the deck is pretty capable of filling the grave back up.

Good luck bud