Drop heads on block break

[I-Al-Istannen]

Taken from Bartooliinii:

I've been enjoying the plugin a lot so far, and so have the people on my server. Thanks for all the help you've already provided. I had a suggestion I would like to run past you and see how much work it would be for you or how enthusiastic (or not) you are about this idea:

Could you make it so that people can turn on specific custom heads to drop from specific blocks at a certain % chance droprate?
It would be amazing if this could be added in the config or simply with a command like /dha drop [blockname] [droprate] for the head you're holding.

I'm asking, because I thought it would be nice if this was possible during christmas for instance, where people find 'present' decorheads from specific blocks and a server could host a challenge where the first to find all presents gets a reward, along those lines.