You’re holding shares of an Irish fund. On distributions made by Irish ETFs through a clearing system (like in your case), no tax will be withheld. Thus, where no tax has been withheld, there’s no reason to file DA-1 in this case.
As for the dividend distributions made from European companies to the fund itself, they are simply not your business (so some non-refundable tax may be withheld).
You are of course free to hold EU stocks directly:
Apply for (partial) relief of withholding tax withheld with DA-1.
And then, in addition, request a refund of the remaining amount directly from the foreign tax authority, for a 0% effective foreign tax burden
…in theory. In practice you might incur expenses in doing so, which in some cases could be higher than the actual amount to be refunded. For example, a certificate acceptable to the foreign tax authority might be required as proof of the tax withheld.