I would like to buy a new usb hdd which will be directly connected to my Vero 4K.
I’m not going to connect any other hdd, only this one.
Are there any limitations regarding the hdd capacity (4 Tera, 8 Tera, 16 Tera)? or everything is supported?
No size limitations. I’d recommend that you get a self-powered drive vs. a USB powered drive.
It will be fine. If you’re swapping it between a computer and Vero 4K a lot, you should format it as exFAT.
Otherwise: you can install the Samba or FTP servers to access files on the disk from another computer.