Lies of P does have a great system though where if you die to a boss, your currency spawns outside of the arena so you could pick it up, go back to the bonfire and spend it

Personally I think that when you do stumble into a boss arena with currency unspent it feels like it adds an extra layer of pressure that makes it more fun. Rather than run straight into the boss you have to consider maneuvering around them in order to keep all of it

Im just saying...one of the new weapons is almost like a pilebunker