The host of an XHB must submit a deposit of boons for the privilege. These boons will be graciously returned to that hostist after the results are announced, on the condition that their battle receives sufficient entries (the number determined by variant - three for a One-Hour Battle). This reimbursement is the boonsave. The purpose of such a mechanic is to foster a culture of hosting battles which BotBrs are interested in, and to disincentivise medal- and badge-farming with low-quality low-engagement OHBs.
The BotB IRCBot announces each battle's submissions as they roll in, along with the entry count for the battle. Upon succession of the requisite entry count, the IRC will be filled with jubilant whoops, cheers, and cries of boonsave!!, boons return!!!!, cashback guaranteed!!!!!!, etc. However, if a battle is receiving few entries, and its submission deadline looms near, all gathered BotBrs will be overcome by sympathy for the hostist and their likely imminent boonloss. It is under these conditions that a boonsave entry might be submitted.
Boonsave Entry