Hello @Patrick87
I believe the transmit power feature will arrive as a software update.
The main reason for my reply, though, was triggered by something you said: "My nest that has weak connection is less than 30 feet away from the one that has good connection."
This makes it sound like you may have arranged your units in a line with the primary at one end, one secondary in the middle, and another secondary further out from there. That's definitely not ideal. The mesh interconnect (802.11s) uses a "fewest hops" metric to select the next node to send each packet to. Since WiFi will slow way down in order to get packets through to a very distant station, that means your most distant secondary is talking directly to the primary rather than going through an intermediate secondary. The higher transmit power will help this situation, but it's still not optimal. You really want to get the primary unit located more centrally so each secondary can get a strong direct connection (one or two rooms away from the primary). Running a bit of Ethernet to make that happen is probably worth it both in the short term and even after the higher transmit power feature arrives.
If you want to better understand why the "fewest hops" policy is used, remember that the mesh interconnect all runs on one radio, meaning it uses a common channel. Going through an intermediary means transmitting the same data twice on that channel, using twice the channel capacity. For that to be faster than going directly in one hop, the transmit speeds for both of those hops would have to be higher than twice the speed of the single hop. Could that happen in some conditions? Possibly. But, the mesh itself has no way to know what the current transmit speeds are for every hop. So, it uses the simpler hop count metric (leading to the optimal placement having the primary in the center).
