I made a skeleton build with Strafe included but took out Interloper:
https://underrail.info/build/?HgUFB...AAAAAAADCoAAAAAAADythAT8FKjV-OSEzS8KFI3_Ctd-_
Again modify to your own preferences. Evasion or Uncanny might be interesting though imho with traps, caltrops, shield, mirrors and good Evasion/Dodge should give you decent protection even with just 3 con and psi. I actually start to become interested in trying this myself.
Blindside is one of the feats that might not be all that important. Mediation should be skippable I think since much of your damage will come from sniper rifles.
Just remember that sniper alongside crossbows are the two builds that get stronger the better the preparation, more than imho other builds.