There's a few indie guitar bands on the Thursday like Momma, Julie, Been Stellar.
This is Lorelei is great, although you have to listen to a few songs to get the gist as they've got a really varied sound, even across one album.
I've got Sabres of Paradis, sistema de entretenmiento, Dame Area and Kate Bollinger on my list for that day too. I would say I've got similar tastes, as I've got all your likes on my list, but then I've also got Idles, Brutalismus, beabadoobee and The Dare, so maybe not 🤣
The friend that shared the Robbie information did so before the festival was announced publically (he said there would be a festival on the town moor next summer and Robbie would be playing) and has re-iterated since that he is a definite. They also said another name they were trying for was AC/DC but obviously they will be a lot harder to book due to known logistics and demands. They also confirmed it is indeed 5 day single day festivals. Never been in a position before to share this kind of information but kind of excited to see if it's correct or whether I've been played.