There are products like Rewopol SB FA, Texapon SB 3 with the slightly acidic pH, preserved with sorbates. Check the TDS or SDS. I Think, it has to be OK.
No one said it will be easy. In my portfolio there is 1 commercial product with 4% a.i. in corn oil. Particle size is 90%<3 micron. 3 years stable at RT. 6 months stable at +40 and -30C stable. So, It’s possible
It’s possible. But you need special dispersants and rheology modifiers. Also you have to make your particles as small as possible. 90%<10 micron (better 5 micron).