With enough money and time, anything is possible. There are limited entities with the ability and expertise to port capx and c3p files to other platforms. I suspect it wouldn’t be worth their while to take the extra effort to port over an already exported game. But hey, you could ask them. It may cost a lot more though.
Old console games are made portable by emulators of those consoles.
For construct games a web browser can be considered basically equivalent to an emulator. However performance, having a feature complete browser available, and even rules on certain platforms make that not feasible. Not to mention a lot of other complexity involved I’m not thinking of.
I should also say that an emulator for a console is way less complex to make than a browser.
Anyways, I shouldn’t be the one to ask. Contact the emails of those publishers and ask. They actually are the ones doing it so they know way better than me.
There’s probably a reason there’s not many porting services or super simple alternate ways to port. It’s probably pretty complex to do.
Having reservations about sharing the capx is fine. If they can’t help you otherwise is fine too. But never hurts to ask if they can work with you with your request.
Worst case you just stick to the platforms already available.