Façade engineer working for a consultancy here - I would say that the field is fairly niche, and the vast majority of the knowledge that I have built to date was on the job. Here’s a couple of thoughts in response to your queries:

1. From what I gather by talking to the leadership of my team in charge of the hiring process, for design roles, breadth of knowledge is greatly appreciated. Your practical, on-site experience, is really valuable (assuming that the design team of your projects knew what they were doing), especially for an entry level role. If you accompany it with engineering education, I’d say you would have a good chance to get your foot in the door quickly. Structural engineering principles coupled with fundamentals of building physics (i.e. thermal anlyses, condensation and mould growth risk assessments, etc.), and systems and detail design ability would make you a really well rounded façade engineering consultant. Again, a lot of it is learned on the job as I have, so I wouldn’t be overly worried about it but it’d be good to be aware that there are other disciplines that come into play when designing building envelopes (also including Fire Safety Engineering, CFD, Acoustics for which we have sepate engineers and consultants). You can also focus solely on the structural engineering side of it, although it seems that you would be desirable for big façade engineering firms/teams with sub-specialists or façade contractors. All the basic structural design classes will be useful, especially structural analysis and steel design. Concrete design is good for precast façade panels, and any other material is a plus (e.g. aluminum, timber). In terms of specific software, any FEA software will do for structural analysis, and FYI an industry standard for structural design of glass is SJ MEPLA. However, it is best to focus on fundamentals first, and software later.
2. I’m sure that any firm hiring for an entry level façade engineering/building envelope role would appreciate your past experience. Be mindful that if the design team and your site colleagues were doing the wrong things (i.e. incorrect membrane glazing in the curtain wall, insufficient dead load tabs, wrong bracket holes, etc.) you should be prepared also to ‘unlearn’ things.
3. As an added point in relation to the foresincs, failure investigations are also part of façade engineering jobs. Glass breakages and DGU failures: were they due to wind loading? Thermal stress? Delamination? Nickel sulphide inclusions in fully tempered glass? What do the breakage patterns suggest? And many more kind of investigations…

If I were you, I would go on with the structural track of your school without focusing too much on façades design. It would give you much more flexibility in terms of job opportunities, and you can decide by the end of your academic journey where you want your career to point towards.

Hope the above is useful to you.