We have discussed this very topic several times before on SN, but it seems nobody has really given it a try yet. @µð®øıð is an absolute shame, anyways, but PostmarketOS will allow us to run a full node on many mobile phones, even some from @ÞÞł€.

As for the investment on a 1TB microSD card, you could probably try with a smaller one with a pruned node if ABCore or any of the other projects previously discussed can manage that, which I guess it's highly probable (I haven't tried myself, though).