Hub 4 problems?

It appears that almost each day a new post appears with problems regarding accessing the administration pages of the Hub 4 router that cannot be resolved by a 60s pin reset or any known workaround. This results, for example, in being unable to change to modem mode which would be essential for my LAN due to having various smart devices / local IP needs / port forwarding etc. (all achieved by using my own router).

So my dilemma is that my engineer installation is a couple of weeks away and if the only hubs the they have are 4's, I risk being unable to use my LAN and enter a period of downtime trying to get the hub sorted out. Now I have no doubt the engineer would do everything to get things working, but if not I'm stuck! Therefore I see a couple of options:

1) Is it possible to request a Hub 3 for the day in advance?

2) Walk away, exercising my cooling off rights, as I just cannot afford delays/stress getting a working Hub for my LAN?

Desperately looking for some reassurance on this 😳