dcdebugmask is a bitmap
starting from line 259, you can see a list of flags to set
if you for example you wanted to disable PSR ( 0x10 ) and REPLAY ( 0x400 ) and custom brightness curve ( 0x40000 )
you OR ( 0x10 | 0x400 | 0x40000 ) these together which equals too 0x40410
so now you have all 3 disabled with that hex number