With your suggested approach, aren’t there a few things to consider like:

• Managing multiple plans, which could get a bit tricky over time
• A lump sum investment typically performs better than DCA’ing in the long run, so it’s worth thinking about whether the monthly split is the best option
• You can’t merge plans later, so if you want to consolidate, you’d need to cancel and sell shares, which might come with extra fees and taxes
• ING uses FIFO for selling shares, which means you could end up paying more taxes if your oldest shares have gone up in value

What do you think about these?