I will report back my experiences as follows:

I have 3 MLDs, running on a Pi - Linux from a mac.  I had a 7-port USDB 3.0 Plugable and it never worked smoothly.

I got very curious as to identify why that was the case and eliminated gradually different causes for the instability of the miners - including reinstalling bfg on the raspi SD card, switching the power inlet to the USB hub, adding fans etc. Finally I caved in and got an new USB hub, this time a 10-port Sipolar (as recommended here several times). I also got a secondary desktop fan and disconnected the noisier small fans on the stick.  

I can say that now my miners have been running completely stable, clocked at 800Hz and with the external fan quietly blowing on them generating around 4.5 Mh/s each with a temp in the mid 50C. So, in my case the instability was caused by a combination of not enough power from the hub combined with lack of cooling.

Thus, even others seem to have had no problems with the Plugable USB hub, I would not recommend it, but would recommend forking out the slightly higher prices of the Sipolar hubs. You can get them from either eyeboot or aliexpress (if you're willing to risk it).

Cheers!