I have 2 bikes both with iscg old tabs, one with an XT crank, one with a RF evolve. On the RF the granny bolts are almost in line with the DS spacer and there is not enough room for stinger to fit. Had the same problem trying to fit the same cranks with a BB mounted stinger to a nomad and the granny bolts fouled-I sold the stinger on here.
The bike with the XT crank has a stinger fitted and works perfectly. Don’t take my word for it, measure the gap between your iscg tabs (or BB where a BB mounted one would replace a spacer and sit) and see if there is enough space to accommodate the stinger plate- from the linked PDF the atlas looks to have more adjustment than my evolve so they may have accounted for this problem with later/higher end cranks?