I think they are going for some kind of membership scheme- maybe linked to packages of games - 3, 5........?

Why on earth is it double the price for people who decide on the day they want to watch a game?!

To ensure they get your £££ in advance lol

Because thats the price simple! Like a lot of things buy early get it cheaper

Nonsense.

Why is it nonsense,? Any pay per view live event on sky is cheaper if you commit to it early. Early bird tickets for live game are not unusual. They have these things called seasin tickets, which game for game are cheaper than paying on the day.
Plus it means they have your money irrelevant of you actually tuning in.
Nothing unusual about it

What other PPV events charge the consumer DOUBLE should they be unable to commit to watching in advance?

2 ways of looking at things mate.
Glass half full. PPV price is £10 or discounted to just under £5 if you commit early, well thats a good deal.
Glass half empty. PPV price is £4.95 but doubles on the day what a rip off!
As for not being able to commit before the day! Currently unless your going to work your not meant to be gpibg out anyhow so not sure what yr going to be doing.
Simple solution, if you dont like the pruce dont pay it, and dont watch it

Has anyone ever used Chromecast to TV, from The RFL website or app?

Has anyone used The RFL App or website, to Chromecast to TV live matches, it is easy to do?

What other PPV events charge the consumer DOUBLE should they be unable to commit to watching in advance?
They are not doubling the price on the day, they are actually halving the price if you buy early.