To be honest, you can still come in top 4 in ranked regardless of a shitty start. Build economy and even if you don't get 2 stars, first on carousels helps a lot. By second carousel, you can get a second spatula, combined with your econ that has allowed you to outlevel others, you'll have a huge numbers advantage. Granted, it's a terrible start and you'll likely not get first, I consistently get top 4 if I'm screwed early.
That being said, can't you surrender at any time? I didn't think it was gated. Just press esc and then surrender yeah?
Also, you say champion shards you don't need? Do you mean you're trying to force a comp and not take what's given? Like, you wanna do knights, but it gives you 3 graves, but you don't want graves, so you opt out of getting 2* graves? Or are you saying, you have a whole bench of options and your options never come up?