I have always felt that the modular nature of the B-2 would allow for a RB-2 variant with low-probability of intercept SLAR radar and/or imaging sensors in a fairing underneath the port weapons bay that would resemble back to back from two modules of TSSAM. For that matter, a KB-2 with the long-range tank in the starboard weapons bay and either a l-o drogue or flying boom deployable from the port one, would be suitable for refueling aircraft of even higher classification.