Are these the cookie consent things? It doesn’t block them, I recommend consent-o-matic extension.
Is it necessary for the VPN to be constantly activated to benefit from the block?
Yes
Is it better than uBlock-Origin?
It’s different. You can use both at the same time. I do and it works great.
When is the page loading speed consistent?
Not sure what you mean by this, but I haven’t noticed any speed reductions using it on Wi-Fi or cellular. I haven’t done any speed test comparisons, though.
On iPhone, does the battery take a hit?
It has to constantly run, so yes. But it may reduce the data downloaded, which will save some battery life. I use it on Android and I think it drains the battery a little faster, so I only use it when I’m on public Wi-Fi.