General rule is to keep it running as a pension except in certain circumstances.
If you have any significant loans or mortgages it would pay to get lump-sum.
Ignoring the lump sum you will receive, does that £45 make a noticeable difference to your standard of living?
Have you got any necessary expenses you have been holding off (car, roof etc). Or will be likely to in the coming years?
Assuming you are going to live at least 16 years it’s not a good deal.
I doubt it will only be a small amount of tax on it.
I might pm you more over the weekend.