Misunderstanding of Subnet directive in hosts files

[SVM]

> Since you are using switch mode, you don't need to specify Subnets at all. You
> do need them in router mode. Basically, the Subnet statements tell tinc which
> IP addresses belong to which nodes in the VPN. Also see the documentation of the
> Mode variable.
>

Thanx.

Some more questions:

I have one node behind two masq. NATs and it works just few minutes 
after initial start of tinc daemon. A few minutes after UDP traffic to 
this node from the node it has connected to cannot travers double NAT, 
and I understand this.

1. But, if I use TCPOnly=yes option, which is deprecated as I've read, - 
it works fine, with non directed traffic, which flows via third node.
If I leave TCPOnly=no(default) tinc cannot determine itself to use tcp 
instead of udp in my case as it described in documentation.

2. As I know from doc, by default tinc uses two connections: 
meta-connection(tcp) and data-connection(udp).
But if I turn TCPOnly=yes? Will Meta and Data flow in one tcp-session or 
also in two different?

Thanks a lot, Guus.