Well judging by my experience with the panzerschreck in the files its shield makes you rely on complete muscle memory to hit your shots… probably why it wasn’t added in the first place.
And thus this having a shield I don’t think it would be worth to really add… I guess as novelty event weapon.
It’s not like 20 more mm of penetration is going make a difference against BR2 and BR3 tanks.
80mm is already enough to deal with any tank at the BR, especially axis tanks.