As a child my parents grew organically in substantial home vegetable gardens, so my bias is to grow organically, but it has very much been stumbling along and trying to learn from my mistakes where ideally each grow is an improvement over the previous grow.
I think one thing to bear in mind with organic living soil, is that it is all very well to have a water only approach, but to my mind it depends not just on the container size but also how long you veg for and how big you grow the plants in veg. I tried to do that this year with my Godfather OG which is growing in a 50L (13gal) container, some folk suggest that to grow with water only, you need to have at least a 30gal container. Because you are following the Rev's TLO approach with the nutrient spikes I assume you would be able to get more to the soil and roots when the soil nutrients are getting used up.
But one thing I realise for folk who grow indoors, that usually from size or time restraints they do not grow their plants as long in veg as outdoor folk may do. So on that basis it seems to make some sense that someone doing a shorter veg period in a smaller pot will be able to do so fine with water only. But in the same sized pot if you instead veg for 4 or 5 months then it is very possible/likely that you would need to top dress or else grow in bigger containers if you want to be water only. But the spike approach is a very interesting way to supplement the soil with extra nutrients during the grow. It'll be really interesting and I am sure very informative to watch your approach as you seem to really be going all out to make it a comprehensive success (you'll have to now, as you've got Emilya watching! haha).
One thing I realise with growing cannabis is there are a lot of different approaches that folk use where they still get great results. I have read of those who feel certain that up-potting to grow the root ball is the best way. And I think only last week I saw a post where someone had grown out 3 of the same cuttings in 3 different pot sizes with the result that after 1 month there were 3 different plant sizes (the biggest grew in the biggest pot), that poster stated they were adamant that from then on they would not up-pot in future. I don't know what is best, to me it seems similar to the defoliation or the no defoliation approach, something which I am still unclear on which is better, the arguments seem to have some basis either way you look at it. But when I see some big plants that have been grown in the ground without up-potting it makes me wonder if it is necessary. But of course when growing indoors I can appreciate there are other considerations that effect the approach people take.
I imagine re-amending will come down to the volume size of the pot and the desired length of vegging time. I tried to do that with my Godfather Og but it became clear her leaves were lightening and would only get worse if I didn't step in and give her a top dress. But it is very interesting what you are doing with the layering and spikes. I look forward to watching the progression of your grow, it is really good stuff what you are doing!
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