Here is a Solution to keep Sublist headers in place when scrolling in NetSuite. This has been a huge help when dealing with any transaction or record that has many order lines or many sublist lines. Enjoy!

It does work on Sales Order, this gave me a good idea I would share if I made it as a native SuiteScript script which does not need Extension...

That would make sense. A client script that does the same JQuery calls. Please share when you do it.