Adding JMertin but that should be fine.
This is covered in https://docops.ca.com/ca-apm/10-3/en/administrating/cem-configuration/networking-alternatives-for-cem/about-cem-insertion-locations
It has the following
Between the Network Load Balancer and the Web Server
Insertion location E, between the network load balancer and the web server (or servers), often provides visibility into the client IP address. In order for this to occur, "preserve source address" must be enabled in the network load balancer if it is acting as a proxy. Insertion location E almost always provides visibility into the server’s IP address.
If the network load balancer uses persistent connections, the load on the TIMs is decreased when the TIMs are located here. The decrease in load is a function of the reduction in open connections, which might be significant. If the network load balancer terminates SSL on behalf of clients and does not re-encrypt the traffic, then the load on the TIMs is further reduced in nearly all cases by a significant amount.
Because the TIM uses the server IP address for evidence collection, there are significant advantages to using insertion location E. However, insertion location E has some disadvantages that insertion location D lacks. Since there might be many web servers, there might be many insertion locations. This might make it impractical to use taps for insertion location E.
Insertion location D and insertion location E are functionally equivalent when port mirroring is used. In many cases spanning a virtual LAN (VLAN) is all that is necessary to use insertion location E. For insertion location D, simple port mirroring might be sufficient.
Note: For more information about TIM and network traffic, see TEC1693123.