My pleasure, I was wondering the same regarding distributing funds and found this in an older FT thread (reply by Ops team in '18):
Are there any FX fees for VUSA? As VUSA is traded on the LSE in GBP there are no FX charges for trading. The only FX to bear in mind is in relation to dividends as the income for this ETF is paid in USD, Freetrade don’t charge any FX fee for this but Crest will convert it to GBP.* CREST is the central securities depository for markets in the United Kingdom and for Irish stocks.
I’m not sure if this is still the case as this was a reply before FT built their in-house investment platform.
For accumulating funds, I would assume the reinvestment of the income follows a similar process as buying/selling securities within the ETF and any fees would be part of the ongoing charges of the fund, i.e. the 0.22%.