Yes, I use an old Qnap 412 as recording storage and an usb stick connected to the masterbox as timeshift folder.
But I can not recommend the box as client, there's an aspect ratio problem on certain 4:3 broadcast with hardware acceleration enabled, same problem on my arm tablet, Samsung 12". Without hardware acceleration the aspect ratio is correct, but the stream lags as hell. This is, so I read somewhere, a problem with the graphic driver on this arm type, not Kodi, not TVH related. Anyway, I don't use the box as client and other clients working well.
Yesterday I tried some different situations with my new setup, recording and streaming, this goes very well, but with descrambling there is something to know. As I wrote before, two boxes, two different logins and it works, so far. Two boxes, one login, on master or slave and it don't work correct. An example: Box 1 has the CA enabled, both tuner are used with descrambling subscription and you record/watch a third channel, which is scrambled, then the stream is running from box 2 and a third subscription is running on box 1, but there's no picture, no sound, nothing. So in the end, this setup is only correct working with two different CA login credentials, one on each box.