The few times I tried to combine LODO with BIAB I put all the grain in the bag and then underlet the pre-boiled mash water into the boil kettle. This was one of the recommendations from the LODO community.
I think my efficiency dropped doing this if compared to my normal approach of adding the grain to boil kettle while stirring the mash water. However I was somewhat paranoid about stirring the underlet grain too much and introducing oxygen which would undermine the reason for underletting so that might explain the efficiency drop.
I never get dough balls. Set up two bags ahead of time. Grind your grist directly into a 5 gallon bucket. Pour dry grist into your bags setting in previously prepared LODO brewing water. This is essentially the same as under letting. I use what I call the DBIAB (double brew in a bag) method, keeps the bag weight less, easy to handle. I use a long stainless spoon. I also use insulating foam mash caps on more oxidation sensitive beers like Helles, Pilsners and IPAs.