Yes, unrelated, but what happens is that gains have their own free limit of £8200 separate from the other limit of £4745. In detail it's more complicated, but you can think of it as the excesses, i.e. gains above £8200 and other income above £4745 then being poured into the same pot, and the first £2020 of that pot taxed at the starting rate, the next £29380 at the standard rate, and the rest at the higher rate.
No, that way you'd lose entitlement to the £8200 freebie.