There are currently no limitations on the amount of data we attempt to stream over the gRPC connection to the block node. This can cause issues with buffer overflows in the gRPC layer and result in some sneaky error conditions. Therefore, instead of solely basing a request on the number of block items, we should also look at ensuring the requests are within safe byte-size limits, such as 4 MB. (For reference, @jsync-swirlds has mentioned that this limit should be up to 8 MB, but we will probably want something smaller than this ceiling to account for any overhead.)