Part of the reason i just keep a certain number of filters in stock, nothing to build up in or on them and if the piece of equipment goes down the road I have less hassles returning the ones that can be returned and don't loose as much as the ones that can't be. However we change fluids filters year round and can't really predict when most of them will need them.
The simple solution to your problem is an ELC coolant. I just use Delo ELC and empty coolant filters. Delo ELC is rated for 8 years/15,000hrs/750,000 miles with no additional additives needed. I still test the SCA's and such though. I buy it pre mixed in bulk for less than $8/gallon delivered. I buy it pre-mixed because there are multiple people grabbing it throughout a day, it just avoids confusion and the half empty jugs that get dumped out because nobody knows what ratio they were mixed to. I guess you could say the water in it is probably a little better too, but the main reason I do it is to keep things simple.
In contrast I can buy good old green antifreeze for less than $5/gallon pre-mixed from same company and it will be good for 2 years/2,000hrs/50,000 miles and I will have to monitor the SCA's much closer and have the labor of changing it that much more often. Doesn't take a brain surgeon to figure out those numbers, not to mention the HD ELC's have much better protection built into them that's needed for wet sleeve engines.
It is important to note that you can overcharge the system by using ELC coolants with filters filled with conditioners, that is why it is recommended to switch to empty filters and add SCA's from a bottle as needed.