I have tried playing 250Mbps 4k h265 from my external USB3.0 HDD, connected to Vero4k. It plays, but with stuttering. USB 2.0 is the bottleneck here. From internal storage, it plays ok. But that was only test file, really nobody is encoding with such big bitrate.
Why I am little sad about Vero4k (or 4k+) not having gigabit LAN and also USB 3.0?
Well, with my old HTPC, I was used to copy new media to its SATA HDD over gigabit LAN. Transfers was about 70-90MB/s, limited only with speeds of HDDs.
I have external 2.5" SATA 500GB in USB 3.0 enclosure, connected to Vero4k. But even with new Vero4k+, and its 1Gbit LAN, it is impossible to reach transfer speeds from before. Because its USB 2.0 bottleneck.
When I want to copy some bigger media to my external USB 3.0 HDD, I must connect it to my PC, do what I need, and then return it back to Vero4k.
Yes, its not as convenient as it was before. However, Vero4k other advantages have outweight this one disadvantage. Bother me a little, but I can live with it. 
If Vero4k+ would have also USB 3.0, except its gigabit LAN, there would be no bottleneck at all.
I hope Vero’s future successor will have also USB 3.0.
I have switched all my devices to USB 3.0, because I realized, that life is too short for waiting for slow USB 2.0 / 100Mbit LAN data transfers. Especially when USB 3.0 and 1Gbit LAN are common things for several years.
Especially, when there is a goal for the device, that is planned to be future proof for 5 years. That is a long time, so it needs to have most fastest interfaces or features to its date. Both USB 3.0 and 1GBit LAN was common things when Vero4k was launched.
Its similar like when you doing cabling in your home overhaul. You will surely not use old 100Mbit LAN cables, you will use cat6a (10Gbit) to make it future proof for decades. Because you wont replace those in-wall cables after few years.
p.s.: Sam, you wrote that USB 3.0 costs too much…can you tell how much, or if there are any problems with implementation? Im just curious. Thanks