I only work for small companies that don’t have any business interest in areas where I want to maintain independent side projects.

When a startup I was working at made a successful exit and got acquired my a major corporation that did have business interests which overlapped with my side projects, I refused the bonus contract and froze my side project activity until leaving about a year later.

Don’t get cute. Avoid side projects that compete with your employer, and disclose unrelated side projects properly so that your employer is forced to acknowledge them. Do what it takes to avoid entanglement, making sacrifices if necessary.