Oh dear i could write a whole book regarding to trade safely. Itīs not only about the payment method. If you go first and you get the PSC after you forwarded yout goods, PSC woulnīt be safe as you would maybe never get it.
PSC is safe in case that you use it directly because it cant get chargebacked as a paypal payment and you should make a video of the whole transaction otherwhise you got a "he said she said thread in the TBM Area" in worst case.
But in case that you want to trade with a member with low tbms i always recommend to use a middleman to make the deal safe for you.
You can find them here:
Of course you should choose a trusted middleman as they are unofficial.
And you should take care that the MM doesnīt check the PSC on his PC as PSCs could get locked when you use them from different IPs. I always prefere to use Teamviewer and to make a video of it to use the PSC directly on the PC of the tradepartner to be sure nothing can go wrong.