@ulrik

Thanks for the suggestion! I researched the Buffer approach with getSlice() and it sounds promising for instant loop/reverse control.
However, my instrument has 100+ samples with velocity layers, pitch tracking, round robin, etc. Switching to a Buffer-based playback system would mean losing all the built-in Sampler features and having to rebuild them manually in scriptnode/SNEX.
For now, I found that setting "Purge All" to "Lazy" in the Disk I/O Settings gives a noticeable improvement not instant, but much faster than before.
Maybe in the future I'll explore the Buffer/SNEX route for a simpler instrument where instant loop control is critical. Thanks for the idea!