Web proxy - multilple GETs in a single packet

I have a scenario where I want to DSCP mark packets with a traffic shaper based on the destination of HTTP traffic. My clients use the RouterOs Web Proxy, which has a parent proxy configured. The traffic shaping device sits between RouterOs and the parent proxy.

The problem is, the RoS web proxy is consolidating multiple GETs from clients into a single packet to send to the parent proxy, so the traffic shaper can’t mark the packets individually.

Does the “Serialize Connections” option on the web proxy affect this behaviour?

Traffic flow:
Client – RouterOs – Traffic Shaper - Parent Proxy – Destination