Best time to add fruit to BOMM mead before or late fermenation

Hi, I have all the ingredients for a 5 gallon BOMM mead. I would like to divide it up after racking into one gallon glass containers and try different fruit such as blueberry and peach/apricot etc. I also have French and Hungarian oak cubes. What is the best approach to to these additions. I was considering a later fermentation so the alcohol will help prevent spoilage. But I am not sure when and how to add the oak cubes?

I’ve made 2 of these and find it takes a little longer than 1 month to be great. I would definitely like to follow what you’re doing for a change up on a great method for mead making.
Following…

This isn’t specifically for mead, but in general you will get much better flavor from fruit additions if you want until after active fermentation is complete and the mead/beer or whatever is starting to clear. The amount of time you want it to be in contact with the fruit varies with the type of fruit, but in general a good 6-8 weeks will allow for good flavor extraction. Fruits with high tannin content (grapes, apricots) should get racked off fruit closer to the 6-week mark to avoid it becoming too astringent, but with any fruit if you wait too long you will start losing some of the fresh fruit character. My rule of thumb is to wait 6-8 weeks before you expect to package before adding fruit, and rack it off the fruit right into your bottling bucket or keg. Depending on what you’re making, this could be right at the end of active fermentation or a year or so later.

As far as the oak goes, I would boil it a couple of times to extract as much of the harsher flavors before adding it to your mead. Err on the low side, too - you can always add more later. Same time frame for oak, I like to give it at least 6 weeks.