why ppl decide to make such statements publicly ?
oh boy !
"the red led not being reliable"
No need to re-post nonsense; it's enough of the demonstration inability to properly describe the feature of the dock.
It is working as DESIGNED !
Frequent blinking without HDD means internal controller POLLING the connector (SATA).
Blinks each time when SATA interface is active, ie read/write/etc cmd getting through is other functionality of the red LED.
[Why it's outside of comprehensions of other ppl, it has different different place to discuss ]