This is just information for other users who have OpManager MSP edition.
Don't know if anyone had already realized it was as simple as this, but just thought I'd share with others what I'd found incase it helps anyone. Unfortunately you still can't push out resource monitors to multiple servers from the central server like you can from the probe, but you can change settings globally.
At present you need to log into the customers probe to set default settings for resource monitors and thresholds etc. But obviously it would be better and easier to be able to do it from the central server as any changes made would then go out to all customers.
You will then be able to edit the central servers default resource monitors and by doing this it will globally apply to all your customers that use those resource monitors, which is handy for a global change to save you having to do it on each probe.