No. but when it's empty it resets only world physics and master-mods configs
If your hands isn't in the ass, and you don't change configures of master-mods it will work fine.
Because what's is duel server? It's XR server with default world prefix duel_ it means that prefix-mods located in /game/mods/prefix will check duel_ prefix and if it found server will load duel configures so it will be duel

. When your server does update all master and prefix mods configure resets and if you had change it, your server backup itself to xr default configure (maybe your mods will disappear

but if your mod is integrated in savage like samurai wars nothing happen.).
-----------------------------------------
Translate for noobs-----------------------------------------
When you download server files DON'T TOUCH IT

! Delete all files in /game/world/. Copy this
http://www.newerth.com/?id=maps&mid=1639 to /game/world/. Copy this magic text: set default_world duel_garden_d; to XR_admin.cfg on line 1 .
DONE!! You have duel server!
How it works?
Your server have magic file located in /game/mods/prefix/duel.cfg - this file make your server run duel if it found in current map (duel_garden_d) duel_ prefix.
How to install mod on server?
Your server have magic folder named /game/python/triggers/library/ it contains most popular mods (server triggers).
To install any mod copy it from /game/python/triggers/library/ to /game/python/triggers/.
DONE!
How create server triggers?
Learn Python

How create mod like xr_N4B?
Learn file XR_admin.cfg (Groentjuh may help you, and I of course

)
And modify commands in xr_admin.cfg

Modify /game/savage0.s2z (I can help) with 7-zip arch.
DONE!