It would be great if the synology integration can include the feature to turn on the nas using WOL natively. Using WOL in home assistant has been quite flaky to use in automations to switch on NAS
What makes you think incorporating WoL in another integration will make it any more reliable on your network?
It will operate exactly the same way.
FYI, WoL is 100% reliable in waking devices on my network. Maybe investigate why it is failing on yours.
WoL is working on all my devices too except the NAS (not reliably) and there is no configuration except the mac id and ip for WoL in HA (highly unlikely something is wrong from HA end). For synology it has more to do with the security firewall. WoL does not work on synology like on simple media devices . I am not a networking expert may be someone who is using WoL on NAS can throw some light. I did find a article Power on and off Diskstation with Home Assistant - Sven's development notes