the requirement is to pay (by today for Q4...) 90% of your 2024 tax due, or 100% of your 2023 tax (110% if AGI was > 150k), whichever is smaller. So I think it depends on your situation in 2023 what this minimum amount due for estimated taxes would be and therefore whether you will have a penalty. If you know the high level numbers you can do a quick draft in TT and look at the results on Forms 1040 and 2210.
Depending the outcome, Form 2210 allows you to specify uneven timing of the tax due to one-offs (a large cap gain, Roth conversion etc) to line up estimated taxes accordingly, otherwise IRS assumes your total tax was evenly due each quarter thru the year and penalize portions of it even if you pay it all in Q4.
More info on estimated taxes here https://www.irs.gov/faqs/estimated-tax
Given this cap gain event, keep eye on same issue for 2025 tax year, you will need to have paid the smaller of - 90% of 2025 vs. 100% of 2024.
Not a CPA/expert just my 2 cents, hope this helps.
