STOXX Europe 600 - domicile and tax


I was recently looking into creating passive investing strategy using etfs from freetrade and stumbled upon this ETF: STOXX Europe 600, ticker: XSX6

Given that this is only accumulating ETF for broad Europe I was looking into investing in it but noticed that it is domiciled in Luxembourg. It also says that it has UK Tax reporting.

Do I understand this right that given it has tax reporting in UK any dividend paid will count towards capital gains (or will be untaxed when used in ISA) rather than income tax? I know this is accumulating ETF and I should not receive dividends but I want to play it safe + it’s just for my information for future investments.