Although I know that there should not be an issue, can I run multiple Exchange Management Shell Export-Mailbox command at the same time? I have my reason for not doing bulk (Get-Mailbox DB -> Export-Mailbox) export, mainly due to insufficient disk space. So I rather do it one-by-one, but multiple times at once. Is it OK?

Yes you can.Where Technology Meets Talent

Thanks for that, although I reconsidered because when I tried, it seems that the throughput is still the same because other export command slow down to accommodate multiple instances and utilize resources. Thanks!