BenF
You continue to work small miracles with the Nano FW updates.
If there is enough Flash and RAM, the ability to load bmp files onto the display would open the door to adding PC created Nano SD files that could describe the other SD files present (a custom file listing description).
For example, Photoshop could be used to set the proper canvas/image size in pixels, and then text can be added to that canvas as required. This would create a custom list of available Nano SD card files for loading. Viewing of this file would allow the operator to easily identify filenames for REF files and CFG files for various frequent waveform analysis situations.
This should have it’s own FI pop-up menu load-file choice. The file must conform to your size and dimension requirements, and use your required file extension and SD card folder. Display of this file must not disturb the current menu & parameter displays.
In essence this would allow less skilled people to use the Nano easily and successfully. Users could share these files with others who have similar interests.