Even if you can reconfigure the softswitch not to require DTMF, it is not possible to claim "use vid of foreground call" in fnc=sd definition. It is no issue as long as you are using one switch only. If you are registered to more than one switch, the PSK (or Line) key will initiate bXfer against switch specified by vid= parameter (vid=1 as default). If the current (foreground) call is not related to such switch, the bXfer request will fail.
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