What is the maximum capacity for a Time Capsule's hard drive? I am thinking of buying a Time Capsule with a small hard drive and upgrading the drive to something larger. There is ample documentation on the web as to how to do it, but I am having a hard time finding any details as to what the upper limits of drive size are. It's especially confusing since there are four generations of Time Capsule, and each one may have a different upper limit. So, what is the upper limit of each? And, if you only know the answer to one specific one, that would be great, too.
Nobody seems to know what the official drive size limits are, but I just connected an 18TB hardware RAID to a 1st generation Time Capsule, and it works. To duplicate my setup:

Configure a 4-drive hardware RAID using this enclosure:

https://www.newegg.com/sans-digital-tr4utbpn/p/N82E16816111149

(I used four 6TB drives and set it up as a RAID 5)

Connect the RAID enclosure to the SATA connector on the Time Capsule's logic board using this cable:

https://www.newegg.com/p/N82E16812119251?Item=N82E16812119251

This Time Capsule has pretty much been gutted over the years, so the only thing left is the logic board itself. It's powered by a 2A 5VDC external brick, WiFi and routing are disabled. It's just a hack NAS at this point...but it handles an 18TB drive.