By the way, I reran the calculations, and in my opinion they are slightly misleading.
Apart from the fee differential, there is an assumption that the exit tax at year 8 is paid without selling any units of the ETF. On a 1m investment, that might not be realistic.
Let's say it is. Then for a 'like for like' comparison, the 293k cashflow in the ETF scenario to pay tax should also be included as being invested at the same time in the Investment Trust scenario.
Using fees of 1% for IT, and 0.2% for ETF, and a smooth 6% gross annual return, the IT wins out over longer holding periods, because of the impacts of exit tax.