I dont know if you have serious problems with lightening overvoltage or not. We found that most lightning protection devices will work as an protection against health damage on persons, but will not help to save the devices at all, but we still use them on reasonable places .
Mikrotik has starter to throw back devices like cards or boards with status that they have been damaged by overvoltage. Why ?
We use antenas that are DC short, so as MIkrotik self tells they dont need to be secured by lightning protection. And about ethernet overvoltage? Haha, if we use very stable high current DC source secured by high current bateries, it immposible to becomme overvoltage. Only way is to be directly hit by an lightning, and i will be sure you will recognize that your device was directly hit. We changed some boards at last time that seems to have problem on DC input, and send it to the dealer. They were thrown back as overvoltage damage! WTF!!!! We didnt have an storm, coz we didnt have an rain for longer than 1 month long!
So how they "recognize" overvoltage damage ? I think it is very simple. Some DC overvoltage damaged boards, that have been send back as repaired, was just without one capacitor from the 4set. So i think that if Mikrotik finds an damaged (punctured) capacitor they just say "overvolatge".
Ill better use capacitor with higher voltage resistability instead of annoy customers, but everybody has its own way. I am just remembering ABIT and motherboards problem. They used some wrong supplyer of capacitors and complete one year of motherboard production (cca in years 200x) was afficted and every board needed to be replaced after aproxymatly one year of use, because capacitor was puffed out.
So just think about it and make your own decisions.
PS: We are using APC or the same protectors like you
yes, we do have a lot of board returned back by them and they claim said it's damaged by over-voltage.
but some it's in house use and out of sudden it's not working.
what can we do as they kick it back to us.