The docs tell you how to enable SmartStore on a standalone indexer https://docs.splunk.com/Documentation/Splunk/latest/Indexer/DeploySmartStorestandalone this means it is possible.
But I highly recommend to read this section of the docs as well https://docs.splunk.com/Documentation/Splunk/latest/Indexer/AboutSmartStore#Choosing_SmartStore when you consider to move to SmartStore.
Hope this helps ...
yep i think that makes sense, so similar to how we have it set up today if an indexer goes down we can not search the data on that indexer. With remote storage it will be the same way, each indexer will manage its own buckets locally and remotely.