Manually refreshing a cell with a formula
I started this question/answer because the previous question was dated and closed.
I am using the latest version of Numbers in Mac OS Ventura, which is supposed to work better with large spreadsheets. To update a cell with a formula I simply right click on the cell and the formula result appears. Then I move out of the cell and the updated result remains.
I didn't try this but it should work as well when selecting multiple cells containing formulas. And it should work as well in previous versions of Numbers but again I didn't check this out.
Hope this helps.