The MOT tester's manual also states that no more than two DRLs should fitted.
It also states that cars first registered before 2018 do not need to be inspected (wrt DRLs). I'd suggest getting professional advice before fitting extra DRLs, as opposed to additional driving lights, these should normally only come on when selecting main beam.
What does your insurance provider say? Might be prudent to get their take on adding lights?