Hi Ian, I don’t think I’ve heard of anybody rigging that up, and a plain un-translated rebroadcast certainly wouldn’t work as Zwift iOS doesn’t support serial streams over bluetooth.
What I do know is that Computrainer has been showing off a new head unit that supports WiFi sometime last year. It may also broadcast BLE or ANT+, I’m not sure. The head unit is compatible with all the existing Computrainer units out there from what I understand. I don’t see any mention of it on their website, but I saw it in action personally 4 months ago at a trade show so I know it actually exists.
If you’re looking for something to work in the next couple of weeks, I think you may have to go with your backup plan of getting a PC or new trainer. This computer for $500 USD is an excellent lower cost option: https://www.amazon.com/Alienware-ASM100-1580-i3-4130T-Discontinued-Manufacturer/dp/B00MA7AMKY
Good luck, and if you get any info from computrainer I’d love to hear about it.