Great job.
Yes, OLED looks modern. In the beginning, I also went down the path of creating such a display,
I even bought a suitable display, but gave it up for several reasons:
1) Lack of a display that exactly matches the dimensions of the VFD being replaced.
2) The high price of a ready-made module.
3) Relative unreliability due to the large number of components.
But in general, such a replacement is possible subject to a number of conditions:
- Lack of additional termal and electrical instability.
- Do not obstruct the installation of the AC board.
What I mean. Placing the display controller board in close proximity to thin film resistors can cause additional termal instability.
Unsurprisingly, FLUKE shielded the Z101 resistor circuit, which is located next to the A/D ASIC.
It seems to me that this should be taken into account.
In general, the display has the right to live without distorting the operation of the multimeter.