Yes—extra macro keys can be useful in Lightroom, but mostly by triggering existing keyboard shortcuts or recorded macro sequences rather than through Lightroom offering fully custom shortcut mapping itself.

From the shared experience here, a practical approach is:

• use Lightroom’s built-in shortcuts where available
• use your keyboard software to assign those shortcuts or multi-step macros to the extra keys
• map repetitive tasks like sync settings, preset-related actions, or metadata/keyword entry if your macro software supports text input

One answer specifically recommends VSCO Keys, which was designed to add customizable Lightroom shortcuts and can then be paired with a macro keyboard layout. Another notes that macro keys are most valuable for repetitive actions in your own workflow, especially actions that normally require longer key combinations.

So the short answer is: yes, your extra keys can help, but the benefit comes from keyboard macros and Lightroom shortcut tools, not from Lightroom natively letting you assign arbitrary slider controls to any key.