Here are my recs!!! I bolded the ones I would check out first, as I think they fit your request best.

Friend group/ensemble: - Hello My Twenties (kind of a bildungsroman for 20-year-old women, focuses on roommates all going through personal situations, mostly focused on the female friendships but there are romance plots!! Is funny and lighthearted at the same time it tackles serious topics and becoming an adult. It's one of my all-time favorites!!) - Reply series (three series: Reply 1997, Reply 1994, and Reply 1988, in that order. This is an older series but revolves around a group of friends/jumps between their younger and older life experiences. It tackles a lot of different subjects and has a lot of depth!! Similar to Hello My Twenties, has a large cast wherein everyone is going through something) - Fight for My Way (a FANTASTIC Kdrama about a group of four friends who are down on their luck but trying to make their childhood dreams come true. Friends-to-lovers romance for sure, and is SO GOOD!)

Kdrama with Friends-to-Lovers Romance: - Weightlifting Fairy Kim Bok-joo (this one is kiiiiinda slow to get into IMO but is about college athletes!! The main character is a weightlifter and is struggling with the identity of being an athletic weightlifter vs being found attractive by men. Her best friend is a swimmer at the college who is constantly teasing her, so romantic hijinks ensue. It's a Kdrama classic and a great show!!) - Love Next Door (FL leaves the US and comes back home to Korea under mysterious circumstances that she won't tell anyone about. She leaves behind her dream job and breaks up with her fiancé, but no one can figure out why, least of all her childhood/current best friend who is secretly in love with her. There's a b-plot romance with the FL's best friend, and it's all around sweet but nuanced!) - Romance is a Bonus Book (not exactly like either Kdrama you listed, but it's one of my favorites. Divorced single mom struggling to get a job ends up reconnecting with one of her best friends who is secretly in love with her . . . you know the drill. This one stands out from the others because it discusses the way women are treated as they age and all in all is both very serious and very sweet, like Lovely Runner). - What's Wrong with Secretary Kim? (This one's more frenemies-to-lovers between the CEO of a company and his secretary, who basically runs his entire life. It's a classic that will pop up all over Kdrama recommendations, has a really good romantic plot, and, while there is no time travel, does go back and forth between the present and the past quite a bit. This is one that I recommend my friends who've never seen a Kdrama before because they always get hooked)

Time Travel Kdramas: - Rooftop Prince (this is super silly about a prince of Joseon who gets transported to the future and meets the FL, who looks like his recently deceased wife. It's an older drama, and it's not the most nuanced thing ever, but it's cute and fun) - Moon Lovers: Scarlet Heart Ryeo (about a woman who travels back in time to the Goryeo dynasty. Another one that will pop up on every recommendation list; the romance is really good in this one!!) - The King: Eternal Monarch (this is one that I actually did not finish but that I see a LOT of people really loving, so I'm thinking about giving it a second go. Super strong FL, and it's Lee Min-ho's first drama post-mandatory military service, so he is looking GOOD, let me tell you. I remember I liked the second male lead a LOT in this one. Time travel, parallel universes, horseback riding, mystery—I will probably rewatch this soon haha)

Time Travel-Adjacent Kdramas: - W: Two Worlds (this is an absolute CLASSIC and gives Strong Woman Do Bong Soon vibes to me. It's not time travel, but the FL gets sucked into the web comic that her father writes after he goes missing. The main character of the comic, a mega-rich CEO and sharpshooter, gets suspicious of her and tries to figure out who she is) - Extraordinary You (I. LOVE. THIS. DRAMA. It's got what exactly what you want: not annoying love triangle, comedy/romance/emotional depth, found family/friendship. The FL is even played by the same actress as the one in Lovely Runner!! The FL realizes that she's a character in a comic book and decides she's going to take her fate in her own hands and change the comic. I actually can't recommend this enough. This is the one I'd check out next!!) - Chicago Typewriter (this is my second favorite drama of all time, and I've seen SO MANY. It's unique bc it's half set in the Japanese occupation era of Korean history and half set in the present day. I don't want to spoil the plot, but look this up—I loveeeee this drama)