Value throttling is added in ZBXNEXT-4724, however it means that preprocessing manager now sends historical values to workers so that they can compare new data with old and if nothing has changed then value must be throttled. The problem is that it can be large amounts of data sent to the workers and back. It should be considered to send only md5 hash to avoid moving large amounts of data and thus improving performance of preprocessing manager due to sending less data and calculating hash in workers.