Construct 3 is built for now and the future, using bleeding edge features.
I would also argue that an organisation not allowing updates to browser is a pretty backwards security policy. Unfortunately you'll have to wait for them to allow updates.
You'd be making an unrealistic argument. Larger companies, especially those with security concerns, are typically at least a few versions behind. Every update to every piece of software is vetted by internal IT teams at larger companies and just about every school I've ever worked at or been in. I've worked at places that were many versions behind with Adobe's CC suite for this reason, and while it's obvious not many people are going to hack a computer through Photoshop, it's still a concern for places with organization-wide IT policies.