I remember that threads which ignored this rule were mercilessly deleted. Perhaps the OP should correct this previously written, to eliminate all possibilities of interpreting this as a violation of the rules.
However, I think that the reservation of giveaway slots through PM is wrong, and it looks very non-transparent.
For example, you may use the giveaway manager created by bitmover to determine the winner, and you can accept more than 16 participants.
https://bitcoindata.science/giveaway-manager/I am also sure that you icopress, as an excellent manager, can organize a quality contest that will be transparent and where more users will have a chance to win a prize.
I imagine it like this.
Rather than create a thread in the gambling or collectibles section, UniJoin can create a thread in the archive, and everyone can apply (participants in the UniJoin campaign or anyone who has ever posted in this thread... before UniJoin reported it). So there is no need for this tool (I appreciate your advice). It is not needed since the winner will, as before, be determined using one of the Bitcoin blocks.