I think there's a couple of things to consider. Finding additional support for example seems more like a you-problem and not the publishers problem, and possibly can be avoided with careful planning/scoping. (Not that I have the ability to not woefully overscope everything I touch...)
The export to console is a little bit of a bummer, but in reality there's probably not that much difference I think. Even if the engine technically supports export for consoles, it's more than likely that it will not work out of the box. You will almost certainly have to do porting work, regardless of engine. The only difference would be that you could do the porting work yourself, which sounds like an absolute anti-fun nightmare to me. Ratalaika (aka one of the companies that does porting) covers all porting costs and ports for a % of revenue. At least that's what they told me last time I asked. Sounds like a perfectly fine deal in my book. If the game is well received, it will still be worth porting and as such will still be worth for the publisher, just not as much I guess. Not to mention the publisher will make damn sure they get their share of money either way.
Not sure about sustainability/maintenance to be honest. I'd guess that well thought out eventsheets are similarly sustainable as well thought out code, and terrible code will be just as bad as terrible eventsheets. Also you CAN do a large portion in code if you want.
I guess my bottom line is to worry a bit less about the publisher. And if you show the publisher an absolute banger game, they probably really don't care if it's made in Construct or not.