I just did it last week, and I'm glad I did. I sometimes have a hard time when my T is gone, and it's especially bad if I'm already stressed or upset. It wasn't the same as seeing my usual T, of course, but it was nice to have that time and space to talk about what was on my mind. The backup T was really nice and a good listener. It helped that my T picked her out for me, so that endorsement made her seem trustworthy. Plus I felt free to say whatever I wanted since I knew I might not see her again anyway.