I think that right now "cheating" is fine because of the upcoming Tokyo stuff in a month or two (longer?) since from what I've read it was a "level cap" event last time (Jetah might know). Spending 3-4 hours on an investigation mission is great but not when it breaks your leveling flow if you're trying to get ready for upcoming stuff.
On the other hand a lot of investigations are tons of fun to figure out on your own, but it's going to depend on what knowledge you have. Being able to read Romanian or Greek or knowing the Bible would make something playable to you, whereas I would need to look that stuff up
Aaand you could always just skip them for now. You don't need the bit of exp and the item bags and cosmetic rewards are still good if you came back to do them later.