Here's a list of typical restrictions you might come across.
NFTs minted at once
Unique API provides a method for minting multiple NFTs in one transaction; for bare API -
unique.createMultipleItemsEx, or using SDK -
sdk.token.createMultiple. However, there is a limit for a block weight which could lead to
1010: Invalid Transaction: Transaction would exhaust the block limits error.
The safe limit is 35 NFTs minted at once.