is 'thousand autumns' that slow?

[ english is not this user's first language ]

hey! so... i started watching the donghua of the said title without knowing a single thing about the story itself; since the novel is famous and twitter fanarts got me curious, i gave it a chance even though i absolutely hate 3d adaptations. and guess what? i am actually surprised with how good it is! i catch myself laughing unconsciously — despite the hint of a melancholic empathy for the mc's disabilities — and it's the first time i locked in for this type of animation.

YET the reason i'm doing this post is because i saw another post where a few users were discussing about the novel of thousand autumns being a slow burn, the focus almost entirely on the politics and issues, etc etc. they've said it's like the romance is quite there, while in the donghua the seme is constantly ragebaiting the uke whenever they share the same space.

so i wanted to ask: is thousand autumns a slow burn like sha po lang? i've just started to read the third volume (of spl) and the main focus is not reeeeally the romance. perhaps how the abrupt change of events makes the characters see each other with another point of view — almost like those doctor x police relationships that neither of them have much time to spend together before something happens.

do they get engaged? is it rated +18? do they even confess to each other?

i swear those comments made me disappointed because wdym their chemistry looks so nice but in the novel they will only make a reasonable progress in the 98373829 volume?

& to clarify: i used spl as an example only because it's also a slow burn since the universes are completely different.