SDK has an API to preload file and start file without delay on a special method call. I think you can experiment if it's OK for you.
Please check simple player app -
https://github.com/visioforge/.Net-SDK-s-samples/tree/master/Media%20Player%20SDK/WinForms/CSharp/Simple%20Video%20Player
Update code:
- Set Play_DelayEnabled property to true before Play/PlayAsync call in your code
- Call Play/PlayAsync
- Call StartDelayed at required moment for a fast playback start