Is the /flex2gateway/ still there in CF2021?

First of all, this is NOT about a Flash app or the Flash Player. We know that ship has sailed.

The client has a legacy front-end desktop executable which was compiled from mxml/as files and runs on the AIR application platform - on many devices in a closed network. So, a console, and not a web or browser-based app.

The back-end data & biz rules are provided by a ColdFusion 11 server via a homegrown API that pumps traffic through the /flex2gateway/ daemon.

Obviously they need to migrate to CF2021, right away - IMO. I'd also like them to rework this front end too, but that's a 2 year project at least.

Anywhoo: When I hit the /CFIDE/flex2gateway/ folder on my development version of 2021, I get a plain 404. So it's not there?

Does this mean the support is entirely missing (deprecated) now? Or maybe it's hidden behind some lockdown defaults and config fiddling?

I've heard of a possible solution using Lucee and BlazeDS, but I'd prefer to exhaust the ACF options first.

I know this is a legacy framework. Please don't throw rocks at me. I just want to make these guys happy.