I didn’t compile the 29000 number I got it off HistoryNet. If you have an issue with it take it up with them.
My father was a Marine on Iwo, he thought it was worth it.
It seems to me putting bases in Siberia would have been a huge logistic, re-supply & infrastructure problem particularly in 1943. I don’t have the time, nor inclination to research it.
It would have meant trading a huge infrastructure and supply effort to the South Pacific with a huge infrastructure and supply effort to Siberia. The only difference is we wouldn’t have had to fight for the territory.
History.net is obviously wrong too.