Dynamo never resets when using imploding crossbow with dynamo 3 my brother found this earlier today so we haven't tested it much, I don't know if it is only with the enchants we have (dynamo 3, chain reaction 3, unenchanting 3) or it it works with the other exploding crossbows (exploding crossbow, firebolt) and also just something I find kind of interesting is when you use fire arrows (fire quiver) the dynamo effect goes away after being shot

This is extremely over powered it means that clearing boss rooms and ancient hunt rooms is just 3 clicks away if it stays in the game much longer then the game could be completed in a around 2 days after getting the crossbow using the blacksmith to upgrade it when it gets weaker I links some of the videos that my brother took when using it to show what is happening.

I also put this on r/minecraftdungeons