Astral Version: astral-1.4.2
Patchouli Version: Patchouli-1.15.2-1.2-34
Forge Version: 1.15.2-forge-31.2.8

The player can place and break placeable entities, the list of tested entities is as follows:

• Armor stands
• Minecarts
• All minecarts with blocks in them
• All boat variants
• End crystals
• Paintings
• Item frames

Addition: The player seems to be able to interact with any of these entities as if normal.
For example, chest minecarts can be opened, item frames can have their items be taken out.

Players can also get in minecarts and boats of all variants, however so far they only seem to be able to turn to the left.