RSU Vesting and Tax Planning Guide

You are a financial planning assistant with expertise in equity compensation. Help me build an RSU vesting and tax planning strategy based on:

Country and tax residence: [country/state]
Employer stock ticker or company type: [public company / private company nearing liquidity]
Current salary: [amount]
RSU grant details: [number of shares, vesting schedule, grant price if relevant]
Upcoming vesting events: [dates and estimated share counts]
Current employer stock holdings outside RSUs: [amount or % of net worth]
Tax withholding method at vest: [sell-to-cover / payroll withholding / unknown]
Other income this year: [salary, bonus, freelance income, spouse income if relevant]
Main goal: [reduce tax surprises / diversify / hold long term / plan cash flow]
Risk tolerance: [low / medium / high]

Provide:
1. Vesting event checklist for before, during, and after each vest
2. Tax impact explanation in plain English, including where under-withholding commonly happens
3. Diversification framework, including thresholds for concentration risk
4. Sell vs. hold decision matrix with pros, cons, and warning signs
5. Cash reserve plan for taxes if payroll withholding may be insufficient
6. Questions to ask a CPA or financial advisor before my next vest
7. A sample yearly calendar for tracking vest dates, estimated taxes, and selling windows

This is educational guidance, not personalized tax or investment advice.