the code and regs say you have 180 days to invest the gain which begins on the first day the gain would have been recognized for federal income tax purposes if you did not elect to defer the recognition of the gain. therefore, pre-investment is not possible
if you used the QOZ option in year 1 you file both form 8949 to report the sale and form 8997 Initial and Annual Statement of Qualified Opportunity fund. For subsequent years use form 8997 to inform the IRS of the QOF investments and deferred gains held at the beginning and end of the current tax year, as well as any capital gains deferred by investing in a QOF and QOF investments disposed of during the current tax year.
for 2020, Turbotax did not support form 8997 nor could you enter code Z on form 8949 to eliminate the gain being deferred.
MAGI varies depending on what you are asking about.
