I never knew such a playstyle had existed like that; then again you learn something new everyday.
To answer your question, when I play IIDX on a keyboard my friends and I would play "spread", something like:
1.) Left Shift, zxc space ,./
2.) Left Shift, zxcv ,./
3.) Left Shift zxc m,./
I usually play by using the third method above, my friend uses the first because he used to play O2Jam and DMO or some shit back in the days. To be honest with you, if you're trying to play IIDX (officials), I highly recommend purchasing a dedicated controller to play, something like a US/JKOC with a PS2 -> USB adapter to start off and if you feel comfortable enough, purchase a DAO controller. Or if you want to just straight up play BMS on the keyboard, there's nothing wrong with that.

To answer your question, when I play IIDX on a keyboard my friends and I would play "spread", something like:
1.) Left Shift, zxc space ,./
2.) Left Shift, zxcv ,./
3.) Left Shift zxc m,./
I usually play by using the third method above, my friend uses the first because he used to play O2Jam and DMO or some shit back in the days. To be honest with you, if you're trying to play IIDX (officials), I highly recommend purchasing a dedicated controller to play, something like a US/JKOC with a PS2 -> USB adapter to start off and if you feel comfortable enough, purchase a DAO controller. Or if you want to just straight up play BMS on the keyboard, there's nothing wrong with that.
