Yup, that’s probably the best way to go 
The external power supply is mostly from the USB 2.0 time when most USB ports (except some internal desktop PC ones) couldn’t deliver enough power. But both Vero 4k and RPi3 don’t need external power supply for most 2.5" HDDs…
That’s funny bc I researched it a lot here before I bought the caddy and there are some posts which say you need to have external PSU?
StarTech SAT2510BU2E
As I said… Most.
If there are issue with HDDs spinning up, that’s mostly the solution - adding a PSU to the HDD. But especially the smaller format factor external HDDs don’t need any external power as they are made to run on powered USB 3.0 ports. And those mostly get sufficient juice from the Vero 4k’s and RPi3’s ports. Even many USB 2.0 2.5" external HDDs can draw enough power over USB, if the host socket provides enough Amps.
The problem is that it only works for many 2.5" HDDs because they (try to) draw more power over USB than the USB specs actually allow them to draw. Many USB ports in PCs deliver this power - despite it not being within the limits of USB spec. So, it can be a hit and miss, but in my experience most drives are fine on most USB ports nowadays.
@tefkab23: Please, do yourself and me a favor and replace this enclosure!
Only USB downstream ports are allowed to provide power and the downstream ports here are the Vero ports. USB ports of enclosures are upstream ports which are not allowed to provide any power.
The USB specification does not allow to connect two downstream ports to prevent electrical overloads and damaged equipment therefore “normal” USB cables always have two different plugs at both ends. But this simply concept does not work if one of the ports does not follow the specification which is here the case.
So, in my eyes your enclosure has a malfunction or illegal design and to prevent a future disaster when you don’t think about this wrong property and try to use it for another purpose … eliminate this device from your environment.
It’s normal (but not very well documented) – and used by some of our B2B customers. However we don’t recommend this or even like to mention it because we suspect some users may backfeed the device or try and power it from a TV which may not give it enough power; or even power it simultaneously.
I’d recommend just using the official Vero 4K PSU and not powering the drive externally. You should be OK.
Well I’m pleased about this at least. I’d be a bit effed off if, after having researched it, I’d chucked £20-odd down the drain. I do use the Vero PSU to power that, and the HDD is now power-free and all seems fine.