Let say you have already provided liquidity, if you top up your LP with an additional deposit it would RESET your overall IL Protection to the date of the new deposit. The IL Protection will be tracked from the most recent deposit and every time you add a new deposit the days of IL protection will restart for your whole pool.
So in order to get 100% ILP, you will have to wait 100 days from your most recent deposit.
If your deposit transaction takes a while to process, AKA if the chain of the asset you are providing (such as BTC or ETH) is congested, you may suffer IL whilst your asset transaction is pending. This is because the deposit can only be protected when it has been confirmed and added to the pool. This also applies for pending liquidity pools that have not been granted as an active pool, as your assets are in a pending pool that is “inactive”.