SCCM client used on network access

You may want to read about split tunnel. You can either send all traffic from the client via the VPN, or use split tunnel to select what goes via the tunnel.

You may want to look the DNS settings as well. Make sure you have the internal DNS servers, and maybe static entries if necessary.

Have a look in the manual, it explains these 2 things:

https://support.f5.com/kb/en-us/products/big-ip_apm/manuals/product/apm-network-access-13-1-0.html

About limiting the traffic, there is traffic shaping. I have never played with that, but seems to do the job you want.