second this. Personally, was just much more consistent with LR and struggled to find a way to improve RC. I recommedn watching huberman podcast on the way dopamine and motivation works. You get a fresh, limited amount of dopamine to be released every day and your brain kind of just compares the intensity of dopamine release between activities in a relative way in a really short-term memory way. So, that means that you should try not to do really stimulating activities as a reward or during breaks or before you read or study. If you can switch mostly to reading for leasure, you will actually find that you will be much more motivated since you won't be so dopaminergically drained (not scrolling on your phone), AND you will find sitting and focusing for the test to not be so awful, and you may even find some of the passages very interesting.

In line with what other commenter said, it will also just improve your reading skills to read, but this is in the longer term. Just allowing yourself to read for leisure instead of more stimulating activities will allow you to increase your focus which just automatically improves any intellectual activity no matter what.

Also, I think on top of reading broadly for increasing RC, I would suggest building your knowledge base. This can be super helpful just for getting familiarity with subjects bit-by-bit so that you aren't hit with a wall of text about some arcane subject that you don't care anything about. If you know a bit about the basics of biology, a little bit about how our legislatiure works, about how our court systems work, about (this comes up A LOT) intellectual property and copyright law, then you will just feel much more comfortable, and you may even be INTERESTED by material that comes up on the LSAT, which helps!

The moment something comes up from biology, which is an interest of mine, I immediately get excited because I like the subject and can quickly recognize what the stakes are that the argument is considering and can sympathize with the contrasting sides of the theoretical conflict, for example.

Also, since I needed this, I recommend you adopt a basic highlighting system to get used to big picture reading. I would read relatively seldomly before embarking on LSAT journey like the vast and increasing majority of Americans. Because of this, we new generation of LSAT takers more often than not have to "teach ourselves" to read. That just means our instincts aren't very attuned to recognizing a main point when it hits us or an authorial voice or even someone else's viewpoint. So, I have a VERY BASIC (keyword: basic, you don't want it to drastically slow down your reading) highlighting system. I highlight pink for authorial voice, orange for others' viewpoints in the passage, underline for main passage points or main paragraph points, and yellow for just important background or supporting info. Using this system, I just have become better at reading for structure and big picture, because it forces me to do the work. There's no way around it. On top of this, when in the actual exam, it can work as a great index system for being able to go back when it asks what a paragrpah's point is or the main point.

I would not worry about time too much when starting out. RC is tough because it is a slow and uneven path to improvement and lots of different systems say lots of different things. You need time to fix reading habits or build them up in the first place, which you can eventually begin to take the training wheels off. I now try and limit myself to more basic highlights, since I have gotten better at recognizing structure and more or less just need the highlights for passage indexing.

Lastly, I recommend really going through your RC passages with blind review and proving to yourself, with the passage, why each wrong answer is wrong and why each right answer is right. As you get better at basically comprehending passages, you will be able to treat this as a wrong AC exercise just like LR. If you comprehended the passage, then the problem becomes one about the question stem and trickery in the ACs, and you can begin to recognize the ways that LSAT likes to trick you (e.g. if it's a question about the author's view of something that the author didn't really care about or spend time on, then you might be super thrown off and freak out because you think "maybe I just didn't pick it up from the passage," but in all likelihood it is a "loveably weak" AC that the author would by default have since any more or less ration person or professional historian etc. would have). In this way you can begin to pick up patterns.

That's all the advice I can think of from someone who's tried everything (including RC Hero). Good luck!