[own3mall]

Is it not possible to have more than 4 working bridges defined? What is the maximum limit of bridges one can create? Also, what is the maximum number of virtual interfaces one can create?

I can't seem to get the "Current Bridging Table" to update so that "wl0.4" and "wl1.4" are added to the "br4" bridge.

When I try to use the commands manually (documented on this page
https://wiki.dd-wrt.com/wiki/index.php/Brctl_command):

[egc]

I think for broadcom routers, in the old days (yes your build is really old), three was the maximum.

I have seen commits that the maximum was increased, I think 16 for Atheros/qualcomm and 8 for broadcom but maybe the other way around.

New builds however have their own problems with using a VAP so research carefully the build threads.
The latest build looks promissing:
https://forum.dd-wrt.com/phpBB2/viewtopic.php?t=320385
but YMMV

[kernel-panic69]

@egc, there's a newer build that posted: https://forum.dd-wrt.com/phpBB2/viewtopic.php?t=320446 <-- BUT, I agree, check the build threads. 40189 seems fairly good, but I don't have any complicated bridge and vap setups like the OP. I would suggest, however, not doing a huge jump in build revisions from the OP's current build. That might cause issue, might not. YMMV.