I like the rear wedges / stabilisers . There seems to be more 'dead air' than needed in that central section; I'd look at moving the bulkheads in towards the blade a bit to give you more space for parts in the rest of the frame - it won't affect the strength either way and might save weight by allowing a smaller frame. Also with those bulkheads, adding some cut-outs in the area just behind the box section will save plenty of weight with hardly any strength reduction.

Those small triangular front wedges are going to get hammered by horizontal spinners; of course if NST is retired for next year, you won't have anything to worry about . You might still want to make them out of two layers of Hardox. The floor level front prongs are also going to be spinner bait; depending on how far out they stick, you might find floor scraping spinners like 720 will hit them before you make weapon contact. Based on fighting Demon for years, I would change the prongs to just one wider and shorter prong which will be stronger for the same or less weight.