Hi, my name is ***** ***** I have been in the home improvement and repair field for 20 years. I will be very glad to help you today. The thermal expansion will cause some drop in pressure along with there may be a small leak that is yet undetected. If the pressure does drop any further the system can be topped up as needed. It is not unusual for a system to lose a bit of pressure with time and it could have not been overly pressured upon installation. The minimum operating pressure is 0.5 bar so it does seem that it is at minimum which is fine.
It will not cause any damage. No reason to be concerned. It will not hurt to monitor if the pressure does drop then the heating may go out until the pressure is added again. Otherwise no worries and if the pressure does not drop then no reason to do anything and all will work fine as usual.
You are operating now near the minimum operating pressure which is very good. There will be no issues unless you have been losing pressure. It sounds to me that is the operating pressure you have had ever since the installation. Worst case scenario is that you have to add pressure at some point. Very doubtful that you will and no damage will occur from having to top up the pressure at some point.
You are very welcome.