Relief of trading profits against capital gains and opening years loss relief

Suppose a trader makes a Year 4 trading loss (which qualifies for opening years relief). They claim opening years loss relief, carrying the loss back against total income of the previous three tax years on a FIFO basis.

If, after making the opening years relief claim, there is still some unrelieved trading loss remaining (for example, because of the loss relief cap or insufficient total income in the earlier years), can that remaining loss be set off against chargeable gains of the current tax year?

Or is it necessary to first claim the current year and/or previous year sideways loss relief (against total income) before any remaining loss can be relieved against chargeable gains?