I have had blood tests done annually for many (many, many) years which started when I was in my 20s and racing every week and became very familiar with the markers. I’m not a doctor but this was my layman’s understanding.
Looking at the Run Fit test on that site they are not really doing much you would action, especially as you mentioned nothing being flagged in blood tests you have already had, and they were probably the below anyway.
The blood test is a full blood count, the most interesting thing I used to do was check haematocrit levels. Living at 6000ft it would sit around 48%, back then there wasn’t a test for EPO so you weren’t allowed to compete if you HCT went over 50% - not that it mattered to me, just out of interest. I did work with some pro athletes who had to monitor it though to avoid false positives.
If there is nothing wrong here you won’t change anything.
Cardiovascular - the only thing they will pick up is high cholesterol, you can have that tested in a chemist. (I have hereditary high cholesterol so still have annual bloods for this)
Metabolic - cortisol levels are raise when you are stressed and unless you feel there is an issue, not much you would do about testosterone level. It would probably be more beneficial if they checked thyroid.
Vitamins and minerals - testing this every 4 months at most through a blood test is pointless. They even say this on the site “You can usually get all the vitamins and minerals you need by eating a varied and balanced diet.”
You can buy urine dip sticks that would give you much more readily available information for only a few £££ - glucose, proteins, ketones etc
There are numerous sites that offer dna testing to boost your performance and some pro teams are dabbling in it but it still seems to be lacking a bit in proof. Not saying it doesn’t work, just not convincing enough yet even at a pro level.