Using zk34 compatibility vs both 3.4 and 3.8 servers?

[Will Now <wn...@gmail.com>]

TLDR: With curator 4.2.0, is it valid to use zk34 compatibility mode when
using a zk 3.5.9 client against a zk 3.8.0 server?

I am currently running zookeeper 3.4.6 (client and server) and curator
4.2.0. The goal is to eventually update our server zk version to 3.8.0.
Here is the staged plan:

First, I want to update my client version to zk 3.5.9 but leave the server
at 3.4.6.  Enabling zk34 compatibility mode in curator 4.2.0 seems to allow
curator to continue working properly for us (without the zk34 compatibility
mode I got errors from the server regarding unimplemented op codes).  So
far so good; I can update our clients to 3.5.9 over time.

Secondly, when the clients are all updated to zk 3.5.9 I will upgrade the
servers to 3.8.0. This seems to be a supported config according to zk
release notes.

Finally, someday I will most likely boost the clients to 3.8.0.

I have done some quick testing of using zk34 compatibility mode in the
3.5.9 client against the 3.8.0 server and it seems to work fine.  MY MAIN
QUESTION IS: Is this a valid configuration?

It would be easiest for me to simply always run all our clients in 34
compatibility mode against the servers (3.4 or 3.8) instead of needing to
configure/do something special for clients of the 3.8 server.

I just want to verify that this is a reasonable approach. Anything special
I should test?  Thanks!