Assuming you are trying to optimise for the number of SNMP communications, you could use getBulk() but for pools of adjacent interfaces. For instance if you have to query interfaces 2,3,4 you could do getBulk() for interface 1 wight the maxRepetitions and maxRows parameters set to 3 (the number of interfaces to query).
Those 'isolated' interfaces could be queried individually by putting them at the beginning of oid_args and setting getBulk's nonRepeaters option accordingly.
Regardless of SNMP request type, you could stuff as many OIDs into the request as SNMP packet could accommodate, not necessarily only those belonging to a single interface.