(1) You should check out https://wcroc.cfans.umn.edu/wcroc-news/ammonia-wind (the title specifically mentions "gaining momentum"). (Bear in mind this technology works by making H2 first from electrolysis). There's a half-dozen more of these research groups. Wind and solar electrolysis are sensible because they can be placed next to ammonia consumers that currently have to have ammonia shipped in from thousands of miles away. Unfortunately, your technology is tied to CO2 injection wells, which aren't all that common outside the western US.

(2) I'd love to see your math, but assuming it's not available, let me show you my math: Assume 6000 pounds per acre per year yield of wet grass. Say that's 5000 pounds dried. Model grass as 100% cellulose, which is 6% by weight hydrogen. Assume 100% process efficiency, where you get all the hydrogen out, and it's magically compressed. 300 pounds of hydrogen sounds like a lot, but according to wikipedia, is only worth about 32 cents a pound at the pipe. So my numbers show $100/acre/year. The value goes way up at the "pump", but that's because of transportation infrastructure that neither you nor your competition provide. That also assumes free injection of low-pressure waste CO2, which is not only a fantasy, but presumably ties your process to a location far away from your target market for the H2.

(3) Ammonia solves your hydrogen storage and transmission problem, so my math shows it's way favorable, especially since you're triply tied to a CO2 injection site, fertile acreage to grow your grass, and an H2 consumer. Picking ammonia makes cost-effective transportation to the consumer possible. Realistically, you'd react the ammonia with CO2 to make urea, which is way better than ammonia for both transportation costs and market demand.

(4) Didn't say YC funded you, but you were in their demo day, hence my mention of the YC slot.