Which Idea?
Between idea 1 and idea 2, I am definitely more interested in the development of idea 1 as it allows me to design and flesh out characters and create a comic narrative, allowing me to hone comic development skills that will help me after University. While this is true, I still really like the concept of an underground mobile library, inspired by online shadow libraries that change their domain and IP address to evade prosecution, as well as the literal mobile libraries that existed in England in the 1960s and still today. Unfortunately, with further development of the mechanics, I do not think that I was able to get across the experience of moving around a physical library and evading authorities, as I wanted a cooperative game, meaning that the authorities would have to move by RNG, which isn’t always satisfying. Being a boardgame also made it difficult to make the movement secret but discoverable, and these are the limitations that have led me to conclude that idea 1 is the stronger idea. Since I still like the concept of the mobile library, I will consider taking parts of this idea into idea 1.
What form?
Having decided on Idea 1, I still need to decide on a form that Idea 1 will take. While I initially thought that it would take the form of a simulation/visual novel type videogame in the vein of Papers Please and Sticky Business, others have suggested ideas like a physical choose your own adventure comic (like Meanwhile by Jason Shiga) or an interactive comic videogame (like the Pilgim DLC for Cult of the Lamb).
Here are some notes that I took as I deliberated which idea to take forwards:

As my strengths are not in coding, a videogame would be difficult to approach since I am working on my own. However, a physical comic plays much more into my strengths, which is drawing and designing characters, and will let me develop in skills that I am interested in improving, like narrative design and environment design. Overall, I think that a choose your own adventure comic would therefore be the best game idea to take forward.
While I have been mostly considering a physical comic, it is also important to consider other forms that this comic could take, namely a webcomic using a scrolling format, or some kind of multimedia comic which oscillates between a tabletop roleplaying game and comic. I think that a scrolling format is not conducive to skipping to relevant panels (a common mechanic in graphic novel adventures), and I struggle to conceptualise a more multimedia game since the narrative I want cannot be open ended and I want to have defined characters, including the player character. Due to this, I think a physical Graphic Novel Adventure is still the best form that this idea could take.