Curious, but I’m in no position to test it at the time of this topic’s creation.
Nope. That shield fuctions as an extention of its heath pool.
Short answer: no. WF has a 100% shield pen helix on his ult that would just be broken if it affected the sentry shield. If you could, I imagine teams would build as much shield pen gear and helix options they could and cheese the sentry without too much hassle
Shield penetration was patched out of Incursion sentries. I did check with Oscar Mike and it did work originally but it got removed due to issues with Marquis. I don’t see why it can’t be re-introduced now the map has been redesigned to stop long range sentry sniping. Mind you, I’m happy with how it works now.
For the reasons mentioned above.