If you're experiencing stutters after installing Sim Update 3 on MSFS2024, it might be due to simply opening the EFB to load a flight plan.
I found on my systen that flights using the default 787 were a stuttery mess after installing SU3. These flightrs were smooth before SU3. I then discovered that the stuttering started only after loading a flight plan using the Sim's built-in EFB. In fact, I don't even have to actually load the plan to cause the stuttering. Just clicking the EFB's "Flight Planner" button is enough.
Here's a test you can perform:
1. Start the Sim and select "Free Flight"
2. Select the default "Boeing 787-10 Dreamliner" as the aircraft.
3. Select a relatively "unconjested" airport and runway for the flight's departure. (I like to use KTRI - Runway 23)
4. Start the flight and click the "Ready to Fly" button to place the aircraft on the runway, ready to takeoff.
5. Switch to "External" view and pan around the aircraft noticing the "smoothness" of the panning.
6. Open the EFB from the Top Menu, click the "Flight Planner" button and then exit the EFB.
7. Pan around the aircraft as before and notice the "stutteriness" of the panning (or not if you're system is luckier than mine)
On my system this stuttering remains in effect throughout the rest of the flight session. The only way to eliminate it is to exit and restart the Sim. I have found this issue also applies (to a lesser extent) to the default 737MAX Passenger variant but not the Business Jet variant. Nor does it happen with the default 747, Longitude, and any of the GA aircraft I tried.
If, when using the 787, I input the flight plan manually via the FMC and never open the EFB, my flights are as smooth as before installing SU3.
This post is mainly to provide information to others who may be experiencing this issue.