source IP and source Port persistence using irule - Citrix - (carp vs uie)

This is my limited understanding of CARP:

It is a one-way hash-like algorithm that matches on a "source" and sends it to a "destination". As long as the "source" remains the same, the "destination" will be the same and it is for this reason that it doesn't store any persistence value on the F5 locally.

Now, using the above understanding, as long as the "source" values are diverse at any instance, we should have a better distribution of traffic. I think, if you have many pool members, it will increase the chances of the traffic being evenly distributed.

Least Connections (Member) is my favorite and default algorithm to implement by default. If it doesn't help, then explore other options. I don't think CARP/Hash is tied to a specific load balancing algorithm.

No, you don't have to add persistence records.

Testing - depends on the application, what you are trying to test and of course the resources you possess. If you have a great LT/Stage environment, it is easier to test or you can spin up a bunch of cloud servers in different DC from one of the public cloud providers to see if the load is evenly distributed.