Are you planning on skipping years or going more like every 18 months? If not, once you're borrowed out, you probably just have to keep doing so and you're not really getting anything "more" other than in the beginning. So, maybe you get a contract with all current points and you borrow most of the next years and take this great trip, but if you want the same accommodations next year.... you still need 2 years of points but if your current are nearly gone, you can't.
My intention was always to bank and borrow in some capacity. We were assuming we'd get 2 trips spaced about 11 months apart on 1 set of APs and then skip a full year and repeat. So, we were to be using approx 3 years points for every 2 trips.
I have to say the one thing I didn't comprehend before buying was how messed up your points can become when you are borrowing and do any sort of changes to your reservation. Even something as simple as a 7 month switch.
I'm glad I have a "low points" home resort (BWV) so I can book there at 11 and then if I try a 7 mo switch to a "higher points" resort, the borrowing is less of an issue. If it's opposite, you're borrowing more in (or reserving less nights) for your 11 mo booking then you may need for your 7 mo booking.
I had to cancel a reservation (with borrowed points) at some point and getting everything all aligned has been kind of a mess even though I haven't lost any points (yet). I ended up having to reallocate and could bank 2019 points into 2020, but the borrowing left me with only 5 2020 points. Now (with the covid situation) I can't borrow more than 1/2 of 2021. It's kind of limiting what I can do for a trip before losing those 2019 points.
I don't think you're ever going to get it perfect. You will always be banking or borrowing or sometimes both. I'd prefer to stay with borrowed points as infrequently as possible.
