I think im not really have much hate levels. I am managed frame perfect things on console conditions like sliding glitch in Boiler room. Its might one most frustrating thing ever can made on lemmings without tool assist. I just hear most peoples dislike those frame perfect timings.
IMO lemmings have several style levels. Some endurance levels have long lenght, much skills, but are quite easy to completed. Sharp element levels requires sharp timings, but those are mostly shorth. Puzzle type levels which are cunnings, but releativily short. Speedrun type levels, which have hard timelimit.
I´ll mostly try build all type levels my packs.
I think if you make long pack its some good you will show some harder tricks in easier difficult with easy setups. Neolemmings contains a lot tricks you maybe never are see, so when trick like this goes later levels and you not have any idea about it, its goes impossible to completed level. I´ll techinically like all type lemmings levels. Though i only are good build level using orginal boards. How ever i usually play neolemmings using clear physic mode only, so its not matter much is there special boards or not. Special boards are some messy to navigate without clear physic tool. So i´ll personally favor orginal type levels.
Im not really have hate type levels myself. I can always change level if i cannot figured out it and will back it later when i have more fresh ideas.
I am quite patient player myself. So im not really goes mad if i have to reback level over again. Yeah i´ll know its might be very nasty if level have 20 minutes to lenght and your skills end right before goal line.
I usually used tons practice replays so i can easily navigate it through again with better and also used tons pen and paper. No trouble for me. I am throw much harder and frustrating things with console conditions without tools. Neolemminsg luckily have replays and tool sets. Yeah that was some really painful make on SNES system when i make those max-% min skills challenge. For example this Boiler Room pixel perfect slide setup at end. Its take me over 8 hours attempts.