So, I decided to post my arguments that i use for running an Enigmatica 2 expert modpack for me and my friends.
-XX:+UseG1GC -XX:+UnlockExperimentalVMOptions -XX:MaxGCPauseMillis=100 -XX:+DisableExplicitGC -XX:TargetSurvivorRatio=90 -XX:G1NewSizePercent=50 -XX:G1MaxNewSizePercent=80 -XX:G1MixedGCLiveThresholdPercent=35 -XX:+AlwaysPreTouch -XX:+ParallelRefProcEnabled -Dusing.aikars.flags=mcflags.emc.gs -Dfile.encoding=UTF-8
If you are worried about turning of the watchdog then pregenerate a large area while the server is up but you are not playing on it. That way you can take off a huge amount of load while adventuring and such so the server won’t crash that easily.
Hope this helps.