Do nt go by general rules of port area, because they do not take into consideration power requirements or port velocity (indirect parameter). There are two possible errors with lowering port area. 1. Increased potential of port noise
2. Decreased efficiency and coupling capabilities
So, if you want to challenge yourself with those two possible factors of decreasing port area, make sure you know what you are dealing with as far as power. A balance between the two needs to be met to get the most out of the design if you do not plan to increase dimensional volume.
In this scenario, the ideal layout is great that you have. Just have to make sure it works in all aspects of the design.
I can tell visually right now, that it was correct to say the port may be quite long. BUT this can also increase the low output NOT FROM TUNING, but from correct phasing. SO, in reality, if you want more out of a design, (listen up all), do not give port area a limitation, and do not give port length a limitation UNLESS you are limited physically in dimensions and space. Then those factors need more controlled attention.