Preparing to inform main job of my startup - I will not Promote

TLDR: Disclosing my side gig for smaller clients in my industry. Need a way to spin it as a positive for my boss. Okay if they let me go but I want to keep the job for a while if possible. I have worked in automotive for close to 15 years, most recently as a business consultant for software clients. Their revenues are easily in the billions. I’m starting up my own small consulting space. My focus is on smaller companies (20-50M) but in the same industry. A lot of us are very interconnected so the chances of me talking to someone for my startup and it getting back to my company is inevitable. My employee agreement requires I inform my company of a second job. To get ahead of this, I’m letting my boss know next week. I’m working on having the discussion from a positive angle. More connections, more experiments that don’t impact our big clients, etc etc. I’m okay if she says “No” and I have to make a decision to leave. However, I prefer to have the job at least for 6 more months because of the stable paycheck and insurance. I know one person who had a successful conversation. For people who have had this conversation and didn’t have to leave, how did you spin it in such a way where you kept your job? What disclosure guidelines did you set? How did you handle conflicts of interest? For example, a lot of smaller clients integrate with the big orgs I work with today. Thanks for any help