finally have some time to continue on with this, I tried the esp32 download tool with exactly the parameters above and the demo files and I am getting an error in the CMD window of .. "imageIsOk()" failed at ....\src\msw\bitmap.cpp(922) in wxBitmap::CreateFromImage(): invalid image even if I only select the bootloader.bin section or any single part. odd .. so I looked at using the esptool.py supplied and copied the loader script from the flash.sh (made for linux), that works but I get exactly the same failed to connect as I do with platformio and also the same timing looking at pulseview, not surprising since both methods rely on esptool. So I ended up adding a 100nF between the B-E of VT1, oddly enough I cannot see any improvement in the timing on pulseview but it programmed first attempt and every one thereafter so I am leaving it in place. perhaps the timing the ESP sees is a little different to what my salaea clone probe is showing.