I love talking about our tavs too, brings me so much joy <3
This will be a long answer so bear with me

For cuddle position it really depends on his mood.

If he´s feeling a bit more confident and big, wanting to take up space, then I think Felyn really loves wrapping himself around his cuddle buddy as much as possible, providing as much body heat as possible. Really just wrapping his legs and arms around, letting them nuzzle against him and into the crook of his neck, one hand tracing little patterns in their back and massaging their scalp. Just really wanting to be a source of comfort and protection for the other.

If he´s feeling.. a little smaller. Liek if he´s had a bad day or he just wants to be held. He loves resting his head on peoples chests, or like, press his face up in the spot behind someones ear to like. Breathe in the scent bc he finds it comforting, like a warm blanket being pulled over him. He´d want to curl up against someone as much as possible, using them as a big pillow he can hug and find comfort in.

He just wants to hold someone or be held by someone.

Now for a beach episode, I think he would enjoy the ocean... but he is really light sensitive and he gets sunburnt easily, So he´d be wearing the biggest sunglasses he could find, maybe even like multiple at the same time to really block out the sun. And then he´s just lathered in sunscreen, the main reason he is so blue is because that´s how he tans, back in the underdark he is more of a dusty grey XD.

He´d be the idiot who´s never tried surfing but is convinced he could do it bc "It´s just standing on a board", and he would end up getting himself hurt.

Oh let me see if I can grab something from Felyn to tell you about that isn´t super depressing,, anything regarding his backstory is just pure neglect and repressed depression on his part so it´s not really the most fun to get into the nitty gritty unprompted haha.

But the general gist is that he grew in a super super strict and religious noble house in Menzoberranzan, where he idolized his matriarch to the point of believing that she was an avatar of Lolth herself. So he tried to do anything and everything to please her, to gain her affection- failed miserably bc she didn´t think he was special enough, just a lil ant to her. 300 years of servitude and pretending to be something you are not to fit the societal standard he was supposed to fit (A strong leader, fierce and harsh, not giving into anything but his own ambitions... and being a woman, big reason he didn´t transition until post game)

A fun little positive thing I can tell you though is that Felyn adores cuddles, back home in Menzoberranzan he was forced to sleep with one eye open and wake up before the light. So now that he is just traveling around doing whatever he wants, he loves sleeping in, staying in bed for as long as possible and cuddle with those he loves (platonic and romantic). To him there is nothing that feels as safe and comforting as laying in bed with someone you cherish, holding them tight and enjoying the warmth of the blankets and pillows.

(also thank you so much, that´s so nice of you!!!)

Okokok, so I do have a modern au with some friends! So Felyn is a pt (personal trainer) focusing a bit more on gender affirming exercise... tho he is known to be a lil intense with the workouts. Otherwise he lives in a cheap flat bc he is piss poor after leaving his very toxic, rich family that may or may not have done some shady business that Fel may or may not have been involved with cough cough very much so involved cough cough. He picks up minimum wage jobs here and there to support himself and his boyfriend/situationship/it´s complicated, Astarion, and takes a lot of the pictures for Stars insta.

Now if bg3 Fel got isekai´d into that world.... he would hate it, it would be so boring "what do you mean I can´t pick fights with everyone and leverage being as strong as I am against anyone????.... I LIVE IN A BORING APARTMENT!?"