Currently the Hubspot connector syncs current state and property history tables for native objects, but custom objects only get current state tables. For instance, we use an 'Account' custom object to reflect our product structure (a company may have multiple accounts with different contacts, accounts are not always associated with a sales deal, where italics indicate Hubspot objects).

├─ deal
    ├─ DEAL
    ├─ DEAL_PROPERTY_HISTORY
    └─ DEAL_<ASSOCIATIONS>
├─ account
    ├─ ACCOUNT
    └─ ACCOUNT_<ASSOCIATIONS>

I'm requesting custom objects also have a property history option to enable tracking of fields over time. In the same way that you might track deal size over time, we would want to see, for example account revenue over time.