One further thought - another advantage of the umbrella approach is that rebalancing between funds is not a tax crystalling event (because it's treated as a "fund switch" within the umbrella) whereas in the non-umbrella basket of ETFs it is - so you pay exit tax if the ETF you sell is in the money, and forgo a loss forever if it's not. It's also extremely complicated in terms of keeping tax records if you are investing small amounts regularly, as the OP proposes, because you will end up with multiple "slices" of the same underlying ETF, each of which has its own tax base, it's own 8-year term etc. Same is true of the insurance policy basket, but at least the insurer's systems are doing the calculating for you.
Just in case anyone thinks this is an abstract issue, take this example. I invest €100k in a US equity vehicle and €100k in a Japanese one. After a period, one is up 50% and the other down 50%. In an umbrella, my tax consequences are identical to my economic ones - I've stood still, and I can do whatever I want with the investments without having to warry about tax impacts; but if I crystallise in a non-umbrella wrap, then I owe €20,500 to the Revenue (€50,000 x 41% on the gain) even though I've made no profit overall, and if I sell the loser fund, my €50k loss cannot ever be utilised for tax purposes.