Thanks for taking the time to write an overview/review and provide feedback, I genuinely appreciate it! It's good, actionable feedback, giving me something concrete to work towards.
Different 'brightness' of sounds is one area I'd like to expand upon, though for now they do lean a little brighter like you say to provide the most flexibility. Heavy hammers would be a nice addition for sure! I'm hopeful I'll be able to source and record more material eventually, and for some suggestions I may not need new recordings at all – in the meantime though I hope the library still proves quite useful (and fun to use!) for bread and butter slashy sounds.