OK, the lasergate blocking the button is back. I'm grateful that you took the time to play and caught that before the Jam submission time expired, the ending is indeed really weird with the boss standing there lol. I'm too used to how things *should* work at this point, I'm sometimes blind to such issues. Fresh eyes are a big help.
I also updated the grenade activation, I compromised so that now it will execute automatically if you interact with the furnace, or you can use the item while standing at those coordinates.
I'm glad you enjoyed the combat mechanic too, thanks again!!