Darryl’s Analysis

Environment:
The current location where you have it is suitable in terms of light.  It might grow even better right up close to the window: maximizing the view of the sky is the first priority to get good “bright indirect light”.

Effort:
Your watering strategy sounds good.  To minimize future appearance of brown patches, it’s good to occasionally flush the soil so excess water that drains through can leach away built up minerals.  This is harder to do in a very large pot so maybe 2 or 3 times a year will do.  Obviously, the pot must have a drainage hole in order to do the flushing.  IMPORTANT: although this flushes out built up minerals, it also flushes out nutrients so be sure to keep up with fertilizing. And remember that this only minimizes the brown patches – you can never completely prevent it!

If you want your plant to grow well in the long run, you must use fertilizer – more info on fertilizers here.

Expectations:
The reality is older leaves will eventually get brown or yellow and will fall off by no fault of yours.  Browning can never be reversed or completely prevented.  As long as the overall plant is healthy and growing in the right light (which yours seems like it is), then I’m fine with older leaves eventually dying off.

If you want to learn a healthy, balanced approach to houseplant care, check out my online course or my book.