Endless Ocean 2 PAL version is the first disc that has the 4.2, it's possible the USA version will also be 4.2.
If you run this update you will update 4.2 and lose out of region backup loading capability, your USA discs will still work bbut your Euro/Jap ones will now. You will have to set your drivekey to block all updates. Sometimes the modchips are set to block only out of region updates, to prevent bricking your Wii.
If you do not update then you may find that these games will not work because they require certain IOS to be installed on your Wii, something which when you are pure hardmod is going to be difficult without actually running the updates. Nintendo have effectively blocked the upgrade path that hardmodders use to keep their Wiis up to date with latest games.
The solution: Softmod, install ISO manually.