The following objects are not supported for incremental backups because of Salesforce API restrictions:
ApexPageInfo
AuraDefinitionBundleInfo
ChatterConversation
ChatterConversationMember
ChatterMessage
CronJobDetail
DashboardComponent
DataType
FeedAttachment
KnowledgeArticleViewStat
KnowledgeArticleVoteStat
LoginHistory
Publisher
RecentlyViewed
ThirdPartyAccountLink
TwoFactorMethodsInfo
UserAppMenuItem
*__ViewStat
*__VoteStat
qbdialer__isTriggerConfig__mdt
Note: The software performs full backups on Salesforce objects that do not support incremental backups.