Edo, did you ever find an answer to your initial question on how to make Stereo into Mono? If not, I have a workaround, I export the sound as a Mono, unfortunately, you can only do a mono output in a 16bit format. I need to check if the new update now allows Mono export in 24bit. Hope it helps.
I must be old becuase i only work in 16bit 44Khz .My roland w30 is 12bit.I use machine when im lifting samples and working with Maschine i will only work using Mp60 or s1200 sample emu