When contributing so much, just direct new investments into international and bonds until you reach your allocation. No need to sell anything.
As for bonds, it is a tough decision. If you can tolerate seeing your net worth halve over a couple of years and not knowing when it will stop dropping and if it will take a decade or more to recover, then not much need for bonds.
If you are like most of the population and will worry and not be able to sleep every night for months or years because of this, then you have found a use for bonds.
For example, lets say you have 1mil
In a 50% crash, 100/0 will drop 1,000k -> 500k
In a 50% crash, 70/30 will drop 1,000k -> 750k
That smaller loss might be enough to stop you panic-selling and facing unnecessary stress as you see a decade or more of sacrifice disappearing. Many panic and sell low which crystallises the loss and ensures they can never recover from it.
A wise person once posted over on the bogleheads forum -
If you can reach your financial goal with savings alone in just a few years, why take the extra risk and return if when it works out with a lower allocation, it doesn't matter? Do not gamble on something if even when you win, it does not matter to you. You are guaranteed to lose.
