I checked the values in the KB on one of our new 11.0.1 NPM instances that appears to be experiencing the same issue with SAM monitors already (and its only got about 100 managed nodes at this time, with two APE's).
The setting for PollMethod already appears to be using BulkRow:
(taken from SolarWinds.APM.Probes.dll.config):
<SnmpProcessProbeSettings BulkSize="10" PollMethod="BulkRow" MaxProcessCount="30000" RetryCount="2" Timeout="2500" />