Since you did not mention being the spouse of the decedent, I'll assume that you are not an EDB for that reason.
As an EDB, you are permitted to opt into the 10-year rule (and thus avoid RMDs in years 1 through 9 but being required to distribute the entire remaining balance in year 10) only if the decedent died before their required beginning date for RMDs.
It seems unlikely that opting into the 10-year rule would be beneficial unless you expect your marginal tax rate will be lower in the future by year 10. It would likely be beneficial to take annual RMDs plus additional amounts to top out your current tax bracket, allowing you to move the money to capital investments outside of the inherited IRA where they could enjoy gains being taxable at long-term capital gains rates instead of as ordinary income. Of course if your intent would be to place the money outside the inherited IRA in investments that would not be potentially taxable at long-term capital gains rates, that would not be a factor. If you will be taking out amounts sufficient to satisfy annual RMDs anyway, I see no reason to opt into the 10-year rule.
Remember that RMDs are the minimum required to be distributed in a given year. There is no statutory maximum distribution.
