I have been upgrading the firmwares on the NanoVNA, NanoVnaH4, the tinySA, and the tinysa ultra since they first came out and have never had any troubles using Windows 7. I don't have to rename files or any of the convoluted stuff you talked about in the iOS system. The only problem I have had is with a new HP laptop that has Windows 11 and only three USB 3.0 ports which makes the uploading of the firmware very slow. The dfu demo program makes it as easy as turning on your machine.
Dave