A surge protector may (if it can) do some good to the load instead of doing anything bad. The real problem is that you can not see or tell how many times it had actually worked and saved your equipment. There is no indication, no measurement of the good work it had done.
Such surge protectors have MOV (Metal Oxide Varistor) inside which is the key component absorbing energy from the spikes/surges over a certain voltage level. Once it absorbs a spike, its life is reduced. That is just like a battery - you have a finite life.
I have always seen the MOVs already installed inside Inverex inverters. Adding an external device will not interfere with or harm the load/equipment connected.