Wait for another confirmation from someone but I had to offset my callipers 5mm inwards towards rim on each side to use stock monster 900 discs which I believe are 10mm offset. I had spacers made for that. Math is simple. Before I had dedicated spacers I used 2mm bunch of spacers to space disc out by 2mm and 3mm bunch of spacers to space callipers inwards for testing.
Not read all the posts so not sure what you are doing. Can you not machine 5mm from the caliper lugs? 749/848 discs are the same fitment.
848 have 320mm discs, 1098/1198 have 330mm discs however fitment is the same just that the larger discs require a 5mm spacer (and 5mm longer bolt) for the caliper.