As far as I can tell from #zabbix IRC channel, users are concerned about the current implementation of ZBXNEXT-3006. The problem is that all dependent values will get a value every time master item gets a new value. This is not ideal in the case when bulk request result consist of rapidly changing metrics and slowly changing metrics. Naturally one would want to poll rapidly changing metrics more often while having new value of slowly changing metric less frequently to keep database size (and graph performance, and other things) under control.

My suggestion is to provide a preprocessing option that would only pass through every other, or every third or every fourth... value.

Or subsampling can be based on minimal time since previous value.

Or (but this is a bit different thing, kinda solution for ZBXNEXT-1846) subsampling can be based on whether value changed from last time.