37M NYC, $1M portfolio, heavy tech/AI concentration in taxable…sanity check on dilution strategy

New to Bogleheads and need this type of strategy to focus on life instead of market conditions.

Soft retirement target 52–55 with a $4M goal.

The problem I need help with:

My taxable brokerage account is heavily concentrated in AI and tech, individual names plus tech-heavy ETFs. Trying to shift towards low fee diversification.

Current approach: staged monthly deployment into VTI and VXUS to dilute the concentration over time rather than selling winners and triggering large capital gains. At a 50% combined NYC/NYS/federal marginal rate, forced selling is painful.

1. Is gradual dilution via new money the right approach for tech concentration, or should I be trimming winners more aggressively despite the tax cost?

2. At what concentration percentage does a single sector become dangerous enough that the tax hit is worth accepting?

3. Fee-only fiduciary advisor… worth a one-time consultation or better with tax advisor?

Does anyone have experience with NYC based fee-only advisors?