The aspect of speaker placement and near wall placement is extremely complex and it's far more to this than just the simple properties of closed box or bass reflex, according to my experiences some closed box speakers need three feet to the front wall while some bass reflex or transmission line speakers may be placed very close to wall, and it's not about boundary compensation solely....
Well this is my claim, but I can't prove it !!!!
One example:
from my own experience.
I do have a pair of closed box Duntech PCL-15's, the response is extremely flat and well, they are not designed to be set close to a wall, so when you do this they simply sound bl¤##%¤ awful, like a broken old radio, extremely bad, and it's not only about frequency response I believe, or perhaps it is.... at least they seem to be completely lifeless, there is no precision, of course the upper bass region is quite affected by this close to wall placement but it's also a complete loss of stereo perspective, musicians seem to be completely "floating" around the room, just boring to listen to.....
Put the same speakers 6 feet from the front wall, quite close to the side walls and quite extreme angling..... and it's simply astonishing pure magic, just waaaaah
maybe it's frequency response, polar response, many other things..... I don't know but I spent more than a few months's to find an optimal speaker position for these speakers in one room, they are small, simple, and should be easy to position, and it's not like this at all.
Second example:
Other current speakers that I do have, a pair of Meadowlark Kestrel 2, they are transmission line and the TL ends in the front, so they should be less susceptible to near wall placement but still having the TL loading at the bottom I believe they should be somehow difficult in that aspect.... put the speakers almost anywhere in the room, even quite close to any wall and it works quite well.
These are two differences from two speakers that are different in construction, but still quite similar in other ways, two way, 1st order x-overs, flat frequency response, quite similar polar response, both have 6.5" woofers.
Some differences and many similarities but I have no idea why they behave so extremely different relating to near wall placements.
I never tried Boundary compensations, it would change the performance a bit but nowhere near close enough to make the Duntech's work near front wall......
Probably only one way to find out what works and what doesn't
TRY IT OUT