Front Coil Spring - how important to replace?

just to revisit this thread ....
I never got round to doing anything regarding this as I kind of forgotten TBH as there really were no symptoms of a problem so went out of my mind.
Went for an MOT a week ago and .... yup, you will have already guessed .... Failed on Spring. Now I really didn't have a problem with that and in a way I was pleased as the MOT Tester is doing his job properly and I prefer to know if there are problems that need sorting.

Interestingly they didn't suggest doing both springs and juat gave me a price for the one side. Quote of £130 parts & labour to do the work was ok as well I think so just got it done. (I had planned on a DIY job as mentioned before but TBH it would have been a pain to do and at the price quoted happy to just get it sorted by them).
Overall cost for the day was £460 for the MOT, Coil Replacement, an Air-Con Recharge which I requested and a basic Annual Service, so that was all reasonable enough.

What was a bit annoying is that the next time I went to start the car after the service it wouldn't! took about 8 goes to get going and was ok after that - until the next day when the same thing happened. Checking with garage they thought Engine Coolant sensor and searching internet tended to confirm this thought.
Seems when this sensor fails, the engine thinks it is hot and I guess adapts the fueling? (the symptoms were very much of a fuel starvation nature). Garage quoted £80 to replace. Decided to buy replacement sensor from Motor Factors (£13) and fit myself and it seems to have resolved the issue.

Always suspicious that you get a failure immediately after a garage has worked on the car but I suppose those things jut happen sometimes.