Ask the salesman for a blindscan demonstration in the new Duo 4K. I doubt you even get a reply.

If blindscan is available, then why not list it as a feature?
If Vtuners or USB tuners are supported, why noy list this feature?

The answer is simple: Vu+ has crap drivers and expects the image groups to work around whatever driver issues Vu+ has.
Blindscan and Vtuners are not listed because if there are problems with these features, Vu+ can say they are addons. Addons are not advertised features so Vu+ may or may not fix them.

Look no further than the blindscan data and you will see 2018 Vu+ crap drivers.
2018 Vu+ Zero 4K C band blindscan Data Output:
[Blind scan] cnt : 10 , data : ['OK', 'HORIZONTAL', '10796478', '30002000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_OFF', 'FEC_5_6', '8PSK', 'ROLLOFF_35']
[Blind scan] cnt : 10 , data : ['OK', 'HORIZONTAL', '10870993', '28001000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_OFF', 'FEC_3_4', '8PSK', 'ROLLOFF_35']
[Blind scan] cnt : 10 , data : ['OK', 'HORIZONTAL', '10920210', '30000000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_OFF', 'FEC_5_6', '8PSK', 'ROLLOFF_35']
[Blind scan] cnt : 10 , data : ['OK', 'HORIZONTAL', '10999312', '30001000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_OFF', 'FEC_5_6', '8PSK', 'ROLLOFF_35']
[Blind scan] cnt : 10 , data : ['OK', 'HORIZONTAL', '11033129', '30000000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_OFF', 'FEC_5_6', '8PSK', 'ROLLOFF_35']
[Blind scan] cnt : 10 , data : ['OK', 'HORIZONTAL', '11070747', '29725000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_OFF', 'FEC_5_6', '8PSK', 'ROLLOFF_35']
[Blind scan] cnt : 10 , data : ['OK', 'HORIZONTAL', '11118850', '30000000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_OFF', 'FEC_5_6', '8PSK', 'ROLLOFF_35']
[Blind scan] cnt : 10 , data : ['OK', 'HORIZONTAL', '11154305', '30001000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_OFF', 'FEC_5_6', '8PSK', 'ROLLOFF_35']
C band does not exist in Vu+ world so we are forced to blindscan using universal lnb and convert. Totally unacceptable for a 2018 driver.

2018 Edision OS Nino Pro Blindscan Data Output:
[Blind scan] cnt : 14 , data : ['OK', 'HORIZONTAL', '4180000', '30001000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_OFF', 'FEC_5_6', '8PSK', 'ROLLOFF_35', '1', '-1', '0', '-1']
[Blind scan] cnt : 14 , data : ['OK', 'HORIZONTAL', '4140000', '29270000', 'DVB-S', 'INVERSION_AUTO', 'PILOT_OFF', 'FEC_AUTO', 'QPSK', 'ROLLOFF_35', '0', '0', '0', '0']
[Blind scan] cnt : 14 , data : ['OK', 'HORIZONTAL', '4100000', '30001000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_ON', 'FEC_5_6', '8PSK', 'ROLLOFF_35', '1', '-1', '0', '-1']
[Blind scan] cnt : 14 , data : ['OK', 'HORIZONTAL', '3980000', '29999000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_ON', 'FEC_5_6', '8PSK', 'ROLLOFF_35', '1', '-1', '0', '-1']
[Blind scan] cnt : 14 , data : ['OK', 'HORIZONTAL', '3860000', '29999000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_ON', 'FEC_5_6', '8PSK', 'ROLLOFF_35', '1', '-1', '0', '-1']
[Blind scan] cnt : 14 , data : ['OK', 'HORIZONTAL', '3820000', '29722000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_ON', 'FEC_5_6', '8PSK', 'ROLLOFF_35', '1', '-1', '0', '-1']
[Blind scan] cnt : 14 , data : ['OK', 'HORIZONTAL', '3780000', '30001000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_ON', 'FEC_5_6', '8PSK', 'ROLLOFF_35', '1', '-1', '0', '-1']
[Blind scan] cnt : 14 , data : ['OK', 'HORIZONTAL', '3740000', '29998000', 'DVB-S2', 'INVERSION_AUTO', 'PILOT_ON', 'FEC_5_6', '8PSK', 'ROLLOFF_35', '1', '-1', '0', '-1']
Edision knows we have C band and gives the correct output for it.

Vu+ did not list blindscan as a feature for the Zero 4K. so they did not support it. The 22KHz tone in the Vu+ blindscan was disabled so only the low side of Universal lnb will scan. (Unless you inject the 22KHz tone yourself)

Vu+ did not list Vtuner as a feature. There are 4 V tuner slots for the Zero 4K but only two may be used due to a numbering issue.
Both of these issue would be easy to fix but VU+ could not be bothered with it.

Maybe the Duo 4K will be a well supported FTA receiver with a great blindscan. But given the track record and attitude of Vu+, there is no way I will buy it unless it is proven beyond doubt to work as we need it to work.