It's currently not efficient to get any vitality at all or even try to push far, as the RP gain formula of level^1.1 rises so slow you just want to die as fast as possible for the most rp/min, would like to see a change so its actually worth pushing and so that vitality doesn't negatively impact your gain.
Super nova does not reset your current size. Increase Roundness and up costs "NaN 0" when you have max selected and not enough size to purchase. I'd suggest showing the price for 1 when you cant afford it :)