Congratulations Zico, well done.
As Deathstar has said, if you are using a WiFi link then the only connection required now in "headless" mode is PSU, as reported earlier in this thread, would not advise powering the RPi 3B+ from the modem USB socket as the power consumption is over 500 ma. at times, best to maintain a separate PSU for this RPi model.
Regarding DSLStats program revision updates, very easily done maintaining the "headless" connection mode, just download the new revision on your RPi, un-zip, halt DSLStats, modify auto-start file (and desktop shortcut if applicable) to new program path and instigate a RPi re-boot, your personal settings will be retained as configuration files are stored in a different location to the main program files.
Disconnect VNC session then re-connect after the RPi re-boots, should now be running the new DSLStats program revision.
I find I can even do this remotely on the 2 RPi Zero W's I look after running DSLStats at different locations.
If you wish to connect to your RPi across your LAN from a desktop or laptop PC at file level, I find that FileZilla Client (free use program) is very easy to use for file transfer or any other house keeping operations such as periodically archiving stat's history files to NAS / PC, other utilities are available.