This is a really simple idea though I have no idea how hard it would be to code.

Add an item that repels enemies, whether just sylestis, just monsters, just people, or all of the above. It doesn't have to remove all enemies, just make them less common to encounter.

I know we currently don't have many story chapters, but even just working through what we have, I'm only on Astryl's Tranquility and its been 5 years since I've started! One of the things making it take longer is the amount of enemies and how much the current gameplay loop is repetitive (which is another thing that could be worked on, but I think this is a simple fix for now!). however, as stated earlier, I'm not to the grove yet and that could change my perspective.

This item wouldn't affect rare sylestis or bosses. It also wouldn't necessarily affect event zones or the grove (either of which could have separate items).

While I agree enemies are sometimes annoying, Astryl's Tranquility is not very long, I think the reason why enemies are especially annoying to you is because if your current party is your usual party, it has all the wrong gear.

Your air pet, which is a physical element, has Evoker gear, which is gear for magical damage.
Your light pet, which is a magical element, has Myrmidon gear, which is gear for physical damage.
Both are also way lower level gear than your team is.
Your shadow pet has no gear at all. (Would also ideally need gear for tanking/magical damage)

More about gear here!

Overall, while this is an okay spread for a team, this makes it quite a weak team and is likely the reason it takes you this long. Lost Grove will feel even slower for you at that rate! I sent you a few gear pieces for your pets, it's LG starting gear, so it should give you a boost for quite a bit :D You'll have to however level your shadow pet by two more levels ;P He can use what your Nixi is currently using.

But, to get back on topic, I do agree as well that it would be interesting if you could control what types of enemies one could encounter. I could do with a Sylesti boost in LG sometimes! Or ward off at least those pesky sprites sometimes...

oh my gosh, thank you!

i didnt really know gear had THAT MUCH of a difference! ill be sure to double check it!

I also forgot to add gear onto my shadow one, just switched it in today :p

Yeah gear is pretty important! I got told I have trouble in late LG because of my gear the other day, so even later on there's lots to consider :D