Yes I've used that kind of bag in production areas. Forklifts can be used but only in low risk.
I'd consider foreign matter issues and certainly that was an issue in the past, both with the forklift and frame etc.
For the gluten hazard, I'm assuming it's a powdery ingredient? That is a concern. There will be dust released as the bag is opened.
What I'd suggest is some testing where you do a settle test. E.g. you could put some of your product on a tray close to the bag being opened or worst case scenario in terms of distance. Then test the produce by leaving it for as long as the longest breakdown time would be (plus a comfort factor). So for example, if you have a rule where if they line breaks down for 20 minutes, you clear it, I'd leave the tray for 30 minutes. If you have no rule like that, think about worst case scenario, e.g. the line is stopped for break then breaks down for 4 hours if that has happened.
Then I'd test the product from the settle test for gluten. If found, you obviously have a problem you can really quantify. If not, it doesn't mean it's zero risk (but at least it's due diligence).
Either way, if you can, even if you have a room where this is used with other products, you could also consider putting in some white walls around the bag, i.e. on three sides maybe? Separate completely if you can? Another thought could be dust extraction.
But it all comes down to risk and risk assessment. Remember you can't just slap "may contain" on everything as a substitute for control. Also I wouldn't be massively tempted to use smaller hand opened bags instead. Remember that the big pallecon bag is going to be a risk when it's opened but (probably) minimal risk in use. Hand opened bags will contaminate an operator several times a shift who then may walk to and work on another line.
As I get older I am more of a "maybe" person than I used to be. "Technical says no" may still be the right answer but if you can demonstrate to your superiors what the risks are and that you've considered them, then at least the "no" is from a place of putting the effort in and trying to find a way to say "yes". Or at least if you do say "yes", it's "yes but these are the risks, do we feel comfortable with them?"