Critical photos in DIY organic supersoil

Start of week 6 of flowering. Been feeding only tap water with adjusted PH down the entire grow. I topdressed low till a week ago just to be on the safe side, but now noticing some leaf tips getting burned, this is new. The plants looked pristine the entire grow from germination until very recently. Perhaps I am just overthinking it and it is normal senescence. Here is the DIY supersoil blend I created for this grow: https://pastebin.com/pbxMZysq It was my first grow with soil, along with my first grow with photoperiods, and it is also so far the best space filling I've had in my 2x2. In the past I grew from 1 to 6 autos at a time, probably in undersized pots every time, and it is the first grow I actually feel like I know what I am doing! I'm loving this DIY supersoil so far (and so do the plants) but I'll have to see how it does over several grows as it might be hard to rebalance down the line without a proper soil test. I started the seeds in Root Riot plugs, then kept them in coco only paper cups until the leaves reached outside the diameter, then moved them directly to their current 12L fabric pots. I also topped them on the 3rd node a couple days after transplant in the supersoil. The rest of the training was done with RQS training clips, and using a scrog net to space out the branches, I tried to keep them at 6 per plant originally but got a few side branches down the line that looked good enough to keep. I defoliated 4x total, 1x in late veg, 1x 2 day after switching to flower, and the rest was later in flower to improve airflow and prevent overreaching while increasing light penetration. I lollipopped heavily during the 3rd defoliation and removed the leaves at the bottom that I made an effort to keep so far in order to collect leftover light rather than letting hit the pots, as it seemed like the best method to defoliate according to my research. I should also mention that I started to get some tiny flies, maybe fungus gnats late in veg, so I used foliar neem oil spray at a concentration of 2mL/L of ([email protected]) water, along with a few shavings of organic soap to help emulsify the solution without hurting the plants. It seemed very effective at treating the leaves but the soil needed a few more applications and I left no room for chance and combined the neem oil treatment with an organic larvicide for a full soak watering. Since I have left a few organic larvicide granules in the tray and when I water I do not fully soak from the top, only halfway, then I feed half the rest through the bottom tray. I have been pest free since. I also cheated a bit on the no feeding other than water throughout the entire grow and used a flower inducing foliar spray when I flipped to flower. 250ml of solution was enough for spraying the canopy twice and then I didn't add any more. The product was Madame Grow - Flower Karma Induction at maximum recommended concentration. Other than that and the topdressing all the feeding was done through the soil itself. The topdressing was a couple scoops of kelp meal, seabird guano, humic acid, bone&blood meal, dolomite and diatomaceous earth. I'm thinking the tips burning might be from slightly too much guano as I've had issues with it in the past. They call it bat guano but the version sold here is mostly seabird guano, if that makes any difference.