Yes, This has been an extremely unusual year , many homes not entitled to reduction last year, are definitely entitled to LARGE reductions this year. It’s FREE to find out if you are entitled to reduction.
Even if you are under assessed- they cannot raise your assessment unless they reassess the entire area. There is ABSOLUTELY no down side to filing a grievance.
No, a grievance has no effect on your Basic Star exemption.
The tax grievance process can take over a year from beginning to end. However, regardless of when your case is settled, a reduction is retroactive to the beginning of the tax year for which you filed.