To get a head start, start syncing as soon as the splash screen appears.
If it helps, keep it up for a couple more seconds so hopefully the app is synced by the time the main window appears, if it was just a day or two since the app was last launched.
Unfortunately this doesn't seem possible, since the splash screen is loading the native library. As soon as the sync starts, the splash screen goes away.
To get a head start, start syncing as soon as the splash screen appears.
If it helps, keep it up for a couple more seconds so hopefully the app is synced by the time the main window appears, if it was just a day or two since the app was last launched.