
How fast can it go, Sim Update 4 pre-release test build v1.6.23.0 is now available for all players enrolled in the public beta. You can read the release notes here:

Stability & Performance
- Fixed a memory leak and a crash when you’re in Free Flight with ATC open, restart , then stay in rtc
- Fixed a crash in the cabin service navigation graph system.
- Fixed a crash in the METAR system.
General Bug Fixes
- Fixed company name always rendered right to left in freelance when spawning in place where local alphabet is rendered right to left
Traffic
Marine Traffic
- Removed Flight Simulator 2020 ships and replaced them by Flight Simulator 2024 ships for the living world in low graphic preset
Multiplayer
- Fixed Multiplayer nametags not visible over 5 Miles
DevMode
General
- Fixed possible crash in the Aircraft Capture Tool if the selected aircraft is not correctly loaded
Scenery Editor
- Fixed floating simobjects (e.g. flames on oilrigs)
SDK
SimConnect
- Fixed EnumerateSimObjectsAndLiveries interface with Wasm which made the call of this function ineffective
- Fixed SimConnect_SubscribeToFacilities(_EX1) that has been broken on SU4
As you can read it here.