Hmmm! I can't understand why you didn't get good scans from FP4+. I've had some of my best negatives ever on it, and they scan perfectly well. Try D-76 or Ilfosol-s instead of that grain-juice Rodinal.(posted 8312 days ago)
T-max 100 scans reasonably well, but I've had one or two problem negatives from it. Not with grain, but the long gradation sometimes doesn't transfer to a scan very well.
My daughter uses XP2super, and I've scanned some of her negatives with great success. Nothing else at a 400 ISO speed comes near it for 'scanability', IMHO.