Fristly I think you've really misread the position of mainstream GC. Main prominent GCs such as Stella O'Malley and groups like Genspect and Our Duty have openly stated that they want conversion therapy for all trans kids. Plenty of GCs and groups like Transgender Trend blindly defend conversion therapists or even deny that conversion therapy exists for trans people whilst promoting it. The WDI Declaration, which is signed by most major GCs, calls to ban any trans healthcare for children at all and very openly pushes for a situation where the only options are conversion therapy or silence.
Secondly this objection is just rubbish. A conversion therapy ban wouldn't restrict any therapy at all. Conversion therapy is where you set out with the goal of someone being cis or straight, no legitimate therapy does that. That's why we've not seen this problem in any of the 15 other countries that have successfully banned it. Affirmative therapy IS open ended, that's literally what it is.
> There's a cultural conveyor-belt driving gender non-compliant children to interpret their experience as a "trans" one.
This is conspiracy theory territory. The exat opposite is true.