There doesn't seem to be any pages in the manual for openvpn.
Just a page in the wiki: http://wiki.mikrotik.com/wiki/OpenVPN

From the wiki page it appears that a stuff that should be configurable is hard coded.
For example, using subnets within 10.15.0.0

I need to set up a vpn with multiple mikrotik ovpn servers.
And each one will need to use distinct subnets/dhcp pools

I do not see how to generalize the example wiki openvpn to a
vpn with multiple servers. (some servers are clients of
other servers.)

Searching the forum for openvpn I find several complaints
about openvpn stability.

Should I trying to get openvpn, or switch to another
more stable vpn?

From the wiki page it appears that a stuff that should be configurable is hard coded.
For example, using subnets within 10.15.0.0

where did you see that? 10.15.0.0 is just an example...

From the wiki page it appears that a stuff that should be configurable is hard coded.
For example, using subnets within 10.15.0.0

where did you see that? 10.15.0.0 is just an example...

Okay, I see some of the things I missed in my previous look at the openvpn wiki page.

The part I still don't see regards 10.15.30.5.
I see it in a lot of route commands, on the various platforms discussed in the wiki example.
But I don't see it mentioned in any openvpn configuration files.

If it's not configured it must be hard coded. Or, maybe there's a problem with the example.
Or maybe I'm just blind.

Subnets are not hard coded, I can't even understand from where you get such an assumption.

10.15.30.5 is gateway on the Wan side - just an example. you should use your own addressing/gateway