First question: I have a TIM HUB dga4132TIM model, modem router for a 70 mega VDSL 2.4 / 5ghz connection; at the moment the router function is carried out by a set of DECO P7 which transmits powerline about 60 MBs in download and 20 in upload; so I would like to know if by replacing the TIM HUB modem router with a new wifi-6 protocol modem VDSL I could have better performance on my DECO P7 or in any case increase the fiber speed.

Second question: I have two apartments separated by a reinforced concrete floor with different electrical systems.
At the moment the P7 DECO, which I mentioned earlier, downstairs work as a powerline in 5ghz frequency, while upstairs I have a set of three M5 decos that work well with 5ghz, so they manage to transmit about 55/60 MBs too, each one.
Could the wifi-6 modem also improve the performance of these DECO M5s?

Third question:
since the TIM HUB modem router transmits the connection to the deco p7 master with an ethernet cable of 30 cm, how come about 10 Mbs are lost (from 70 MBs found on the web interface of the modem to the 60 MBs of the deco P7)?

Thank you

Giulio