I'm looking at getting a second box and trying to get a grip on the difference between Fallback Tuners and Client Mode.

I've got a Vu+ Solo 4k with DVB-S2 FBC built in, a twin DVB-C/T2 card and an external Turbo DVB-C/T2 card. At the moment I've got DVB-C on the external turbo and DVB-T2 on the twin internal. I've got a 2TB HDD fitted in it and a house-wide wired Gigabit LAN.

I'm wanting to fit a second box in another room, and both boxes need to be able to watch channels on all 3 media, and play and set recording. I'd also like to get more DVB-C tuners. So I came up with 2 possibilities...

First is to keep Solo 4k where it is, and get a Vu Uno 4k SE with a C FBC card and say another 2TB HDD. I'd then change the turbo tuner to a 3rd T2 tuner on the Solo 4k. Then (with both boxes on the LAN, with fixed IP addresses) use fallback tuners to share the tuners across both boxes. So each box would be able to watch and record multiple S2/T2/C channels.

The other solution is to get a Vu Ultimo 4k with S2 and C FBC tuners, swap the twin C/T2 and turbo C/T2 into the Ultimo and fit a 5TB HDD inside it. Run the C/T2 tuners all in T2 mode. Then (with both boxes on the LAN with fixed IP) put the Solo4k into Client mode in another room and use all the tuners from the Ultimo, to watch and record/play on both boxes.

So what I want to know is...

Which method will work the best?
Can I record/play back on both boxes in each set-up?
How are fallback tuners configured on the remote box?
If using fallback tuners do I have to re-scan both boxes when there is a line-up change, or just the box with the tuner thats changed?
If using client mode can I record/play on both boxes, or just the server box? Can I play server recordings on the client box and vica-versa?
Is there any point keeping the Solo4k if I get an ultimo, or would a kodi client do the same (I use Kodi as a client and zapping & playing can be slow)?

I'm sure the answers will drive more questions.

I've posted in this sub-forum because the questions are about fallback tuners and client mode, not the Vu+ hardware itself. So please can this thread be kept in this forum.