Yes and no. The problem how to set up a third network adapter has been solved. The soulution ha been tested over some time, it ha been tested with port scanners and diverse hacker tools and there is no problem. On the other hand this third adpapter problem is solved using the only way, I guess it can be solved, by taking a look into the underlaying Netfilter firewall. On the other hand, the only way of solving the 3'rd adapter problem is not considered as a "illegal" way to modify the SME server. When "the only way" is considered to be "the the illegal way", then this problem will remain to be unsolvable, until the method that will solve this problem is accepted.
When it comes to the question of making access from restricted lan and wlan zones, hotspots etc, this is a question that can also be solved quite easy using the UNmodified SME 7.3 firewall.
I will try to make a WIKI Howto for this last variant. (Just found out how to make logon for the WIKI.)