Keyboard shortcut for moving between tabs?

@PeterSHarps 

You can try the following 2 scripts. Note: as the scripts work by document name, it is expected that all open files have a unique name.

Script 1 of 2: 

Key Document Pair Bookmarker - Set.jsx

1. Run the script to set the first key document.
2. Select the second key document. Hold down the OPT/ALT key and run the script again to set the 2nd key document.

Script 2 of 2: 

Key Document Pair Bookmarker - Get.jsx

Run this script to toggle/cycle through the two key documents. You can assign a custom keyboard shortcut to this script once it has been installed in the application folder's Presets/Scripts folder and restart Photoshop if running.

https://prepression.blogspot.com/2017/11/downloading-and-installing-adobe-scripts.html

/*
Key Document Pair Bookmarker - Set.jsx
Script 1 of 2
v1.0 - 25th February 2024, Stephen Marsh
https://community.adobe.com/t5/photoshop-ecosystem-discussions/keyboard-shortcut-for-moving-between-tabs/td-p/14005778
*/

#target photoshop

if (app.documents.length > 1) {
    // Hold down ALT/OPT key while executing the script to set the 2nd key document
    if (ScriptUI.environment.keyboardState.altKey) {
        setKeyDoc2();

    // Set the 1st key document
    } else {
        setKeyDoc1();
    }

} else {
    alert("At least two documents must be open!");
}


// Functions

function setKeyDoc1() {
    try {
        var os = $.os.toLowerCase().indexOf("mac") >= 0 ? "mac" : "windows";
        if (os === "mac") {
            prefFileOutLF = "Unix"; // Legacy = "Macintosh"
        } else {
            prefFileOutLF = "Windows";
        }
        var prefFileOut = new File('~/_Ps-Key-Document-Bookmark.pref');
        if (prefFileOut.exists)
            prefFileOut.remove();
        var setDoc1 = app.activeDocument.name;
        // r = read mode | w = write mode | a = append | e = edit
        prefFileOut.open("w");
        prefFileOut.encoding = "UTF-8";
        prefFileOut.lineFeed = prefFileOutLF;
        prefFileOut.writeln(setDoc1);
        prefFileOut.close();
        alert("1st key document set! Select the next key document and hold down the ALT/OPT key while running the script again to set the 2nd key document...");
    } catch (e) {
        alert("There was an error writing the '_Ps-Layer-Bookmark.pref' file!");
    }
}

function setKeyDoc2() {
    if (File('~/_Ps-Key-Document-Bookmark.pref').exists) {
        try {
            var os = $.os.toLowerCase().indexOf("mac") >= 0 ? "mac" : "windows";
            if (os === "mac") {
                prefFileOutLF = "Unix"; // Legacy = "Macintosh"
            } else {
                prefFileOutLF = "Windows";
            }
            var prefFileOut = new File('~/_Ps-Key-Document-Bookmark.pref');
            var setDoc2 = app.activeDocument.name;
            // r = read mode | w = write mode | a = append | e = edit
            prefFileOut.open("a");
            prefFileOut.encoding = "UTF-8";
            prefFileOut.lineFeed = prefFileOutLF;
            prefFileOut.writeln(setDoc2);
            prefFileOut.close();
            alert("2nd key document set!");

        } catch (e) {
            alert("There was an error writing the '_Ps-Layer-Bookmark.pref' file!");
        }
    } else {
        alert("First run the script without holding down the ALT/OPT key!");
    }
}

/*
Key Document Pair Bookmarker - Get.jsx
Script 2 of 2
v1.0 - 25th February 2024, Stephen Marsh
https://community.adobe.com/t5/photoshop-ecosystem-discussions/keyboard-shortcut-for-moving-between-tabs/td-p/14005778
*/

#target photoshop

if (app.documents.length > 1) {

    if (File('~/_Ps-Key-Document-Bookmark.pref').exists && File('~/_Ps-Key-Document-Bookmark.pref').length > 0) {

        var prefFileIn = File('~/_Ps-Key-Document-Bookmark.pref');
        prefFileIn.open('r');
        // Read the 1st line from the log file
        var getKeyDoc1 = prefFileIn.readln(1);
        // Read the 2nd line from the log file
        var getKeyDoc2 = prefFileIn.readln(2);
        prefFileIn.close();
        // Toggle between the key docs
        if (app.activeDocument.name == getKeyDoc1) {
            app.activeDocument = app.documents.getByName(getKeyDoc2);
        } else {
            app.activeDocument = app.documents.getByName(getKeyDoc1);
        }

    } else {
        alert("There was an unexpected issue reading the '_Ps-Key-Document-Bookmark.pref' file!");
    }

} else {
    alert("At least two documents must be open!");
}

A related script for bookmarking layers here: