This sounds to my (totally non-educated) ear as a potential misunderstanding. These kinds of misunderstanding are quite common even among professionals, as they are often trained to work and think within one jurisdiction and not look at the big picture - which can be totally different.

I've been there, almost listened to the advice of "certified professionals", and I've been able to avoid costly mistakes by being extremely meticulous and searching for better advisors until someone really knows what they're talking about.

That part you copied seems to be about an _existing_ tax liability that just needs to be settled at some point. Moving switches  that "some point" to be immediate, as they don't let you postpone it into the future after you leave. If so, it's not an exit tax, just "settling current accounts".

There is a similar confusing reference to an "exit tax" in this video:

https://youtu.be/XD_97P_L7GA?t=285

...where it seems that _existing_ profits of a company are taxed when the company exits the UK. That's understandable and not an "exit tax" - just the settlement of existing liabilities at that moment. Those taxes would have been due anyway, just later.

I don't see anything about extra taxes incurred because of exiting, except in those future plans.

Again, I might be wrong about any of this, but so can the "professionals" - worth checking thoroughly with multiple professionals before you pay too much! 

 Yes, you've hit the nuance on the head. It isn't an exit tax, but it is a tax that you incur by exiting as you are settling a tax bill you would've had if you'd sold the appreciated assets at the point of leaving.

I found it very difficult to explain that nuance without calling it an exit tax, which caused the discrepancy as others correctly pointed out there is not exit tax.

As you've gone through a similar journey, I always like to ask people, do you know anything I don't know, but should?

Have a great weekend and thanks