This, 100%. This is how I use BunPro, and it’s very enjoyable this way. Don’t bother forcing new grammar that you’ve never seen before. Think about it, if you’ve never seen it, is it really that useful to you? I don’t recommend trying to force yourself to be able to produce grammar before you can at least clearly recall examples of that point being used.
Personally, there’s no point in me pre-emptively learning a grammar point before even being able to remember a single instance of ever encountering it. This is especially true with N2/N1 grammar.
In your case, you’re still studying N4 grammar. You need to get most of that grammar under your belt before learning primarily through immersion becomes even somewhat doable, in my opinion. Pretty much everything at that level is going to be fundamental or extremely archetypal of fundamental Japanese concepts. Heck, even at N3 that is true.
It took me 3 separate solid attempts through 3 different means spread out across plenty of time before N4 grammar truly started making sense to me. There’s no way around it imo. In fact, it might be optimal to separate your learning into 3 separate stages:
- Pre-learning
- Solidifying
- Grasping
My biggest piece of advice is to have AT LEAST a pre-learning phase. In this phase, it suffices to simply read about the point, without adding it to reviews. Aim to understand it, while keeping in mind that the goal in this stage is breadth over depth - the more you pre-learn, the better. Think of it as canvassing the landscape of grammar. Your goal here is to have a rough idea of the meaning for most of the N4, maybe even N3 grammar points.
The solidifying stage can be done in tandem with the pre-learning stage. As you immerse, even if just for 5 minutes, you will encounter a ton of N4/N3 grammar. The problem is finding a sentence that you can actually understand is going to be tough. So, instead, your goal should be to be able to identify and recall details about which grammar point is being used when you encounter it. If you can’t recall details about it (such as meaning and level of formality) - heck, even if you CAN recall details about it - go ahead and re-read the resources you used in your pre-learning phase, and maybe even read another resource on that topic.
Finally, you should be ready to start producing a grammar point (adding it to your BunPro reviews) when you have solidified to the point where you can either very clearly understand the meaning of the grammar, or can remember specific instances of you encountering that grammar point. At this point, your goal is to add to production so you can grasp the point fully, distinguishing it from other points, and comprehending its own nuances.
Even a 3-staged process like this is pretty optimistic. But truly, production is harder than recall - if you don’t have clear recall of meaning, there’s no way you can expect yourself to be able to distinguish and spring out the idea that conveys the requested fine shades of meaning at will (like what BunPro requires you to).
I suspect you are trying to skip straight from pre-learning to grasping. Give yourself the solidifying stage. At the very least, separate your pre-learning and grasping stages into different days - and don’t add it if you can’t remember what you read about it even a mere few days ago.