Custom Monitor for ISP link packet loss

We are load balancing 3 ISP links through F5.

Though the ISP links are UP, there is a certain amount of packet loss observed due to which there are some latency/connectivity issues observed.

Is there a way to create a custom monitor which takes into account the percentage of packet loss from a particular ISP link and keep it's status UP/Down accordingly.

Can this be achieved by an external monitor? If Yes, any suggestions how to?

Any other solutions?