After uncommenting those lines and rebuilding the module, I get this when I try loading it:
2023-02-11 23:15:11,785 [69130-Thread-0] WARN VASSAL.tools.logging.LoggedOutputStream - Feb 11, 2023 11:15:11 PM com.sun.javafx.application.PlatformImpl startup
WARNING: Unsupported JavaFX configuration: classes were loaded from 'unnamed module @4bb63c71'
2023-02-11 23:15:11,821 [69130-QuantumRenderer-0] WARN VASSAL.tools.logging.LoggedOutputStream - Graphics Device initialization failed for : es2, sw
2023-02-11 23:15:11,821 [69130-QuantumRenderer-0] WARN VASSAL.tools.logging.LoggedOutputStream - Error initializing QuantumRenderer: no suitable pipeline found
2023-02-11 23:15:11,821 [69130-Thread-0] WARN VASSAL.tools.logging.LoggedOutputStream - java.lang.RuntimeException: java.lang.RuntimeException: Error initializing QuantumRenderer: no suitable pipeline found
2023-02-11 23:15:11,822 [69130-Thread-0] WARN VASSAL.tools.logging.LoggedOutputStream - at com.sun.javafx.tk.quantum.QuantumRenderer.getInstance(QuantumRenderer.java:283)
2023-02-11 23:15:11,822 [69130-Thread-0] WARN VASSAL.tools.logging.LoggedOutputStream - at com.sun.javafx.tk.quantum.QuantumToolkit.init(QuantumToolkit.java:253)
2023-02-11 23:15:11,822 [69130-Thread-0] WARN VASSAL.tools.logging.LoggedOutputStream - at com.sun.javafx.tk.Toolkit.getToolkit(Toolkit.java:268)
2023-02-11 23:15:11,822 [69130-Thread-0] WARN VASSAL.tools.logging.LoggedOutputStream - at com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:291)
2023-02-11 23:15:11,822 [69130-Thread-0] WARN VASSAL.tools.logging.LoggedOutputStream - at com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:163)
2023-02-11 23:15:11,822 [69130-Thread-0] WARN VASSAL.tools.logging.LoggedOutputStream - at javafx.embed.swing.JFXPanel.lambda$initFx$1(JFXPanel.java:225)
2023-02-11 23:15:11,822 [69130-Thread-0] WARN VASSAL.tools.logging.LoggedOutputStream - at java.base/java.lang.Thread.run(Thread.java:1589)
2023-02-11 23:15:11,822 [69130-Thread-0] WARN VASSAL.tools.logging.LoggedOutputStream - Caused by: java.lang.RuntimeException: Error initializing QuantumRenderer: no suitable pipeline found
2023-02-11 23:15:11,822 [69130-Thread-0] WARN VASSAL.tools.logging.LoggedOutputStream - at com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.init(QuantumRenderer.java:95)
2023-02-11 23:15:11,822 [69130-Thread-0] WARN VASSAL.tools.logging.LoggedOutputStream - at com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.run(QuantumRenderer.java:125)
2023-02-11 23:15:11,822 [69130-Thread-0] WARN VASSAL.tools.logging.LoggedOutputStream - ... 1 more
2023-02-11 23:15:11,976 [69130-AWT-EventQueue-0] ERROR VASSAL.tools.ErrorDialog -
java.lang.RuntimeException: No toolkit found
at com.sun.javafx.tk.Toolkit.getToolkit(Toolkit.java:280)
at com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:291)
at com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:163)
at javafx.embed.swing.JFXPanel.lambda$initFx$1(JFXPanel.java:225)
at java.base/java.lang.Thread.run(Thread.java:1589)