I really don't like to nitpick, but the term "poles" has been misused in this thread, and has become confusing to me.
In electrical switch terminology:
- poles refer to the number of isolated circuits on the switch. A DPDT switch has 2 (D=Double) poles and 2 throws (2 positions). An SPST is an ordinary single pole, single throw switch like an everyday light switch - either on or off. For more than 2 poles, the number is used instead of a letter. 3P21T would be a 3 pole, 21 position rotary switch.
- throws refer to the different positions for a given circuit or pole. ST means one position, the "ON" position". A SPDT switch or contact - which is what you want for powering turnout frogs - selects between 2 positions for a given circuit. In our frog powering case, you are selecting which polarity powers the frog. The 3P21T rotary switch would have 21 separate positions for each circuit or pole - but all 3 move together.
- terminals are the screws or loops on the underside of the switch to which wires are attached. A SPDT switch will have 3 terminals - one for the pole or circuit feed wire, and one terminal for each of the 2 positions. In our case, the frog is wired to the center or pole terminal, and the stock rails are wired to the 2 "throw" (or outside) terminals.
It sounds like you are already using the 2 way light switches (SPDT) for controlling the turnout motor. The frog power would have to be on a separate circuit. Therefore, you could use
DPDT toggle or slide switches, but not the 2 way light switches, to control both switch machine and frog power.
At the moment you throw the toggle switch, the frog changes polarity but the points have not yet thrown. Depending on how your points are wired, you may be setting up short circuits if a metal wheel set crosses the isolation gaps before the points are thrown. If the points are always opposite polarity to each other, and the same polarity as the adjoining stock rail, no problems (you have ideal wiring, Atlas turnouts are wired this way).
Some Peco (perhaps all) turnouts (and some others) are
not wired this way. The points are both of the same polarity, and change polarity when you throw the turnout. The problem with this point wiring and using the switch machine control toggle for frog power is that the switch machine does not operate instantaneously like the control switch does. So until the points move to the opposite position, the points and frog will be of opposite polarity, setting you up for short circuits. In this case, you need to use a separate contact on the switch machine or turnout throw for frog power so that the frog does not change polarity before the points do.
Probably more than you wanted to know, but I hope this makes a little sense.
Perhaps a short and DCC shutdown before the train derails might not be the worst thing.