What is the better way to organize whitelists of external monitoring servers (URL IPs or URL Table (IPs)?

[Sergei_Shablovsky]

Merry Christmas, pfSense Gurus!

What is the better way to organize whitelists of external monitoring servers: URL (IPs) or URL Table (IPs) (which have update period setting) ?

Generally most reputable monitoring services (like Pingdom, UptimeRobot, Site24x7, RootInternet, etc…) have publish their servers lists in several formats simultaneously:

1. TXT file with ipV4 addresses (and may be ipV6 addresses separately);
2. JSON file (the same);
3. Link on php page which returns TXT or JSON file;
4. Link on RSS feed that return list of IPs;

The question is:

1. Which type (IPs or IPs table) I need for 1. - 4. cases (see above)?

2. how to organize all of them in case I need 1(one!) firewall alias on each monitoring service provider (menu Firewall ~> Aliases)?

P.S.
If You know very stable and reputable monitoring service in Your country, please drop here a link (or name of it). Thank You so much!