Stratix products are not supported as Extended Nodes.  only Cisco IE can be Extended Nodes.i have a document to add an Cisco IE to RSLogix.  its old, and is based on older version of RSLogix.  At best its a guide on one way to possibly do install IE....

you are correct in there are only minor differences between Rockwell Automation (RA) Sratix and Cisco IE switches.  from the outside they only appear to differ by the color of the faceplate. however, the Stratix switches do integrate easier into the ...

the "configuring SD Swap Drive" Chapter in the IE3x00 System Management book is currently under construction to update it with current IOS-XE behavior. 

for IE3200,IE3300, & IE3400, the behavior for SDFlash:, Flash: which is primary has changed.  as you've seen. starting with IOS-XE release 17.10.1 on IE switches, the Flash: file system is now primary always regardless if a SD Card is present or not....

is the IE3300 booting up in "install mode" or "bundle mode"?  the note in the release notes is specific to "install mode".   can you try to boot up in 'bundle mode' and see if the issue persists?