Pop-up attached to button is no longer working in TB102

I don't know why, but TB102 has decided not to let me open the popup
from my callback function anymore. Since it's working fine in TB115
there's no reason to waste time troubleshooting. Let's just detach the
popup in TB102.

background.js

@@ -1508,40 +1508,48 @@ const SendLater = {
       return false;
     }
     SLStatic.info("Opening popup");
-    // The onClicked event on the compose action button doesn't fire if a
-    // pop-up is configured, so we have to set and open the popup here and
-    // then immediately unset the popup so that we can catch the key binding
-    // if the user clicks again with a modifier.
-    messenger.composeAction.setPopup({ popup: "ui/popup.html" });
-    try {
-      if (!(await messenger.composeAction.openPopup())) {
-        // openPopup doesn't return a status in TB102, so we just have to assume
-        // that it opened successfully. *sigh*
-        await SLStatic.tb115(async () => {
-          SLStatic.info(
-            "composeAction pop-up failed to open, trying standalone",
-          );
-          let tab = (await browser.tabs.query({ currentWindow: true }))[0];
-          let params = {
-            allowScriptsToClose: true,
-            type: "popup",
-            url: `ui/popup.html?tabId=${tab.id}`,
-          };
-          if (
-            SendLater.prefCache.detachedPopupWindowWidth &&
-            SendLater.prefCache.detachedPopupWindowHeight
-          ) {
-            params.width = SendLater.prefCache.detachedPopupWindowWidth;
-            params.height = SendLater.prefCache.detachedPopupWindowHeight;
-          }
-          if (!(await messenger.windows.create(params))) {
-            SLStatic.error("standalone scheduling pop-up failed to open");
-          }
-        });
+
+    async function detachedPopup() {
+      let tab = (await browser.tabs.query({ currentWindow: true }))[0];
+      let params = {
+        allowScriptsToClose: true,
+        type: "popup",
+        url: `ui/popup.html?tabId=${tab.id}`,
+      };
+      if (
+        SendLater.prefCache.detachedPopupWindowWidth &&
+        SendLater.prefCache.detachedPopupWindowHeight
+      ) {
+        params.width = SendLater.prefCache.detachedPopupWindowWidth;
+        params.height = SendLater.prefCache.detachedPopupWindowHeight;
+      }
+      if (!(await messenger.windows.create(params))) {
+        SLStatic.error("standalone scheduling pop-up failed to open");
       }
-    } finally {
-      messenger.composeAction.setPopup({ popup: null });
     }
+
+    await SLStatic.tb115(
+      async () => {
+        // The onClicked event on the compose action button doesn't fire if a
+        // pop-up is configured, so we have to set and open the popup here and
+        // then immediately unset the popup so that we can catch the key binding
+        // if the user clicks again with a modifier.
+        messenger.composeAction.setPopup({ popup: "ui/popup.html" });
+        try {
+          if (!(await messenger.composeAction.openPopup())) {
+            SLStatic.info(
+              "composeAction pop-up failed to open, trying standalone",
+            );
+            return await detachedPopup();
+          }
+        } finally {
+          messenger.composeAction.setPopup({ popup: null });
+        }
+      },
+      async () => {
+        return await detachedPopup();
+      },
+    );
   },
 
   // Custom events that are attached to user actions within