That guy in the video doesn't know the difference between PWM, MPPT, buck/boost regulation, and a hole in the ground... he also doesn't seem to understand the control schemes of any of the various controllers he tests.
MPPT controllers still use PWM to regulate the charge, MPPT is just a smarter control scheme and that STM32 micro is more than up to having an MPPT control scheme in it.
Anyway - I realise the cheap ones are cheap, but in response:
That's why our setup has many fuses (in & out of both controllers)
MPPT makes very little difference unless you absolutely must get every last bit of power out
Many of the expensive ones are not provably any better (they wax lyrical about them in the marketing but are light on technical deets)
I've had them apart and they're not horrifically badly made
They've worked fine for some time now
Given they're rated for 10/20/30A and your panel will never pass 5A, you've got a fair safety factor
These ones at least show you some vaguely useful info for your £20, expensive ones tend to have a couple of blinky LED's and that's it. £20 doesn't buy you a dashboard battery gauge these days.
If you weigh the difference between a £20 eBay one and a £200 CTEK, you might gain 10~20% performance with real MPPT (assuming the eBay one isn't MPPT) - for a 100W panel that's <24WH/day. If you really need that extra ~20%, spending some of the £180 difference on a bigger battery (or a pair of batteries) is going to be waaaay better value - every time you move, your alternator will dump way more juice back into the battery than your panel can manage, and with only lights, water pump and maybe a webasto to run even a small 100Ah battery will last days with a basic 100W panel + cheap controller topping it off.