There's too many to list but don't worry, overall story plot doesnt change much from WN (aside from LN already surpassed WN by quite a lot), even with some changes have very different arcs.
Welp, you do you reading it early. KDT pretty much swooped in unannounced and mass publishes theirs without permission from the old FTL group (which they are still doing it) and locked the volumes in a paywall. Do note: they ain't affiliated with the rest of the people translating with 2nd...
BronsTL/GlucoseTL are the one doing the FTL for free and originally the one doing the FTL. Though it may need time for them to catch up (currently doing volume 2)
Can’t exactly put good faith on KDT due to circumstances that other FTL groups that frowned them upon (Shoddy TLs, has a history of...
Plot-wise, its somewhat the same but there's many small and big changes that the LN did (especially this current manga arc in particular, it was never brought up in the WN, only either mentions or just outright skipped it) that it warranted a reread.
Well, Light Novel (LN) is still continuing. Currently at Vol 7.5 and Vol 8 is slated to release in Oct 1 this year. While Web Novel (WN) is caught up TL-wise and raws is in hiatus at Ch.291. Do note, LN already surpassed the WN as of Vol 7, so it may be LN-only in the foreseeable future unless...
Somewhat true, I remember correctly Japanese people do get IV-drip if their condition did go south (like any overworked Japanese man. Funny thing is, that the manga did kinda downplay this part. In the LN iirc,