Not to mention a laminar flow hood is unnecessary.
In pharmaceutical manufacture we would use an isolator; however these don't strictly use laminar flow.
However UGLs don't use an isolator, or a mini-cube (small laminar flow hood). Your product is made "sterile" by filtering and use of BA/Solvents.
Assuming you have a clean environment, you are clean and follow basic hygiene procedures you could replace the stopper, if required, reasonably at home. A mini-cube would not add any tangible margin of safety.
Qualification - 23 years as a healthcare engineer, chartered by IHEEM and working in aseptic suites for production of various medications.
Ghoul just likes to flex his theoretical knowledge with no real practical experience to determine what is actually practicable and reasonable.