How will the re-investment work?

[adamu]

I just cannot get my head around this.

Crucially, if you invested 10k and it grew to 20k and you sold and got 20k, only the original 10k would go into the bank account for reinvestment. The other 10k would be a tax-free gain but you can't invest it without using more lifetime allowance.

Ah, this explanation makes sense. Thank you!

I've added this example to the wiki. Further improvements welcome!