@statusquo
I really don't know much about the form 843. I, personally, don't even know if the form 843 is the right one to be used.
I read some of the instructions, and it said it can be filed within 3 years of the original filing of your tax return.
I don't think it affects your 2023 filing in any way....so you should be able to just mail in that form 843 when you're ready...but just get it done in the next couple months.
About Form 843, Claim for Refund and Request for Abatement | Internal Revenue Service (irs.gov)
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
