Trying to find out if I can go directly from Splunk Enterprise 8.2.6 to Splunk Enterprise 9.0
Yes you can. See this Splunk version upgrade documentation:
https://docs.splunk.com/Documentation/Splunk/9.0.0/Installation/HowtoupgradeSplunk#Upgrade_paths_to_...
You can go from any 8.1+ to 9.0.0 without any other versions. But from older you must use at least one middle version.
Splunk lantern guide: https://lantern.splunk.com/Splunk_Platform/Product_Tips/Enterprise/Upgrading_Splunk_Enterprise
Yes - I did exactly that this morning although to be fair it was just my WSL deployment not a large multi-server deployment 😁
