You do not need to perform a full reindex for all changes. You only need to perform a reindex for non-incremental changes, such as modifying an already existing type/aspect/property, renaming or deleting that. If your model contains only one such non-incremental change, than all other changes will not be processed by SOLR.
Reindexing incremental changes does not require anything special. You just need to have Repository and SOLR running, and it should work out of the box. If you have issues, always check your solr.log and provide any error messages you find here.
We have a commonModel.xml file where we defined all the custom models. If i want to add a new model,i go and add it to the file and restart the alfresco. By this way, alfresco is able to pick up the changes but when do a CMIS query the content is not returned, After doing a full reindex of solr we are able to query the content