That's what I am also want to know if can show the proof of 500k thb with digital currency or stock funds but I didn't see anyone . As i know most are withdraw to bank account earlier one month and print out ibanking slip and show to them.
As I heard from some of my friend , they don't ask for the pay slip, but if you can mention on the employment contract, how much the company hire you per month and have the company stamp on it Or just prepare your portfolio nicely . That's enough.
Be relax and no need to worry too much. It's easy to get approved.