Let's take a step back. There are 3 frequency regions of interest, starting with the lowest of the low.
1) infra-sonics up to longest wavelength room mode
2) room modes dominate
3) ray tracing reflections dominate
Here's a good resource for this stuff. I'm talking about Part 2, near the bottom, page 6
Starting now with region 3, high frequencies... these wavelengths are much shorter than any room dimension, behave like light, in that reflections obey Snell's Law - angle of incidence equals angle of reflection - resulting in recommendations to find first reflection points with a mirror. Distances from source to reflection, and reflection to listener matter only in terms of transit time - how long it takes the sound to travel. This is what Toole calls the speaker-dominated region as the loudspeaker's characteristics dominate.
As frequency drops, region 2, wavelengths increase from inches to several feet - comparable to the room dimensions. We now enter the "room dominant" region where standing waves are the primary issue, and line-of-sight no longer matters. We're sloshing water in a tub at the right rate so the waves grow and the water makes a mess around the tub. Room dimensions and distances now matter when they're close to 1/2 integer multiples of a wavelength. In a completely sealed room with no absorbers, you get huge (40db+) peaks and nulls that vary with location and frequency, resulting from wave interference, either constructively (peak) or destructively (dip).
Going even lower, region 1, at some point, the longest room dimension equals half the wavelength of the lowest freqeuncy that can have a resonance in the room. At longer wavelengths, standing waves are not supported, so the peaks and dips disappear and everything gets uniform. The energy has to go somewhere, so it just builds until energy losses equals energy input. Smaller spaces support shorter wavelength modes, so room gain starts at higher frequency. Cars have tremendous room gain; they're tightly sealed, minimizing losses, and they're small, so room gain starts higher up.
Therefore, if your goal is "making my rooms low frequency response as efficient as possible," use a car as your model, seal it all up to maximize room gain, and live with (or treat) room modes.
If you'll again step back a little, maybe the goal could be making "low frequency response as enjoyable as possible?" This approach balances leakage vs reflected energy, and is, I've concluded, how my room works as well as it does. As you decrease bass leakage, you increase bass levels in the room (and make your neighbor happier). How far you go is up to you, but I suspect that temperate dwelling construction will provide some guidance.
I see a room that's nice and tight for bass when all the doors/windowns are closed, but degrades when you open up to those tropical breezes.