I've also had some recent troubles with my cat, "G". He was vomitting up his raw too, but after some fecal tests, he was diagnosed with having two types of harmful bacterial strains that were causing him to feel sick anytime he ate raw. He was also having loose stools, so I originally thought he was having some kind of IBD issue and was trying different types of raw protein for a while. In the end, it was only canned food that he was able to keep down. After a round of antibiotics, he was totally eating normally on raw (started slow and added probiotics). Since then, however, he's been much more leery and careful when consuming raw, but he's now able to eat about 70-80% of it with a small portion of canned and water. He's still verrrry
slow at times, but have found that using different protein sources such as rabbit or venison really helps his appetite more than poultry. If you can get these from your local store or butcher, it may help to offer different types of protein for some variation and interest. Another thing is that both my cats prefer more chunkier
types of ground meat, so using a different grinding plate may help, or try offering them small chunks like in prey model raw? I started mine with small 1 inch chunks of thigh meat, then slowly added chicken necks, also in small pieces. It may take a while for cats to learn to eat meaty bones. "G" still has an aversion to large bones since his vomitting episode, though.
Another tip I found great to help them eat raw was Stella & Chewy's freeze dried meals. It comes in chicken, turkey, duck, etc. Both my cats love these, and technically you're supposed to add water to the pellets and serve as meal replacements. It's quite expensive to feed as meals, so I mainly use those as toppers by pinching small bits and pieces or use them as treats to my cats to finish off "left overs".
I know that high protein and lots water will definitely help ward off crystals by keeping Jeckle's urinary pH balanced (6-6.5). You could also buy urine pH test strips online to check his alkaline/acidity levels when he eliminates, too.
Hope this helps your Jeckle in some way...persistence is key!! Don't give up!