What I have done to avoid blue/taupe/whatever cobras and/or annoying "stand by" loading screen, as follows:
1. Network MTU settings
2. Close other in-background network use
3. Use solo server for this kind of speed missions
4. Wait about 5 seconds or a specific tune when accessing mission menu for the first time, while asap after "stand by" pushed back to previous menu instead of cobras
If you have other tricks please let us know. Thanks!