You can do the manual reset technique with the MiniCore bootloader as well. However, you need to get the timing right for when you press the reset button. The tricky thing is that when you press the "Upload" button in the Arduino IDE, it first compiles your sketch before starting the actual upload. So you need to wait until after the compilation finishes before pressing the reset button. The way to get the timing right is to watch the black console window at the bottom of the Arduino IDE window. As soon as you see something like this:
Sketch uses 444 bytes (1%) of program storage space. Maximum is 30720 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.
press and release the reset button.
Note that when you do an "Upload Using Programmer" via your USBasp programmer it erases the bootloader from the ATmega328P. This means you need do another Tools > Burn Bootloader before you can go back to doing regular serial uploads over the USB cable.
I found why I had problems with USBasp sketch upload : That is working only with verbose checked !
That is very strange. I can't think of how that could occur.