Some goggles do steam up more than others - some are designed to ventilate more. So you could look at changing the goggles. Your PPE supplier should be able to advise. Not sure what you mean by the mask sealing against the face?

As David says – if face fit tested correctly the masks won’t/can’t leak & goggles won’t steam up (from this cause anyway). Wearing a half mask for a considerable period of time is uncomfortable – but probably better than a series of disposables (disposables should be ‘disposed’ of after every use – normally for heavy use this is considerably more expensive than a half mask.) If you do go for disposables you’ll have to face fit everyone (again?) - & you’ll find a greater failure rate too. You can get air hoods, which I’m told are ‘lightweight’ which continually blow air across the face of the user – most larger PPE suppliers will hold these. You don’t say what the operation is but can extraction be improved with on-tool extractors?