it's an actual spinoff, aside from the character's relationships it's not even in the same continuity
Chloe still being a kid while Rimuru also being friendly with the vampire lord is proof of that
You don't really have to worry about being spoiled if you've read up to vol 7 of the original LN. There's nothing that hasn't already been covered at that point since the only thing that really gets spoiled is the vampire/maid's identity and that's covered in Vol 7 already and the town having ramiris's dungeon included. It's just a collection of slice of life stories that use the same cast.
Meanwhile flamire is a side story original character she and all the stuff around her have nothing to do with the main story. So if you're worried about spoilers it's not really going to spoil much and it's kinda a waste to skip out if you're a fan.
Thanks for the info, I got extremely put off from it a while back when the state of Veldora got spoiled in the very first chapter despite the official LN not being caught up that far. Man that was frustrating.
It should be said. If you're following along with the main manga or the official light novel, it's not recommended you read this just yet. This happens quite some time after the current point in the manga in particular.