The Tri-coupler needs some tweaking

[CaptainShark]

This is a fairly minor issue, but one all the same: it's been around for a while, but the tri-coupler can be very finnicky when used, either in the VAB or space plane hanger.

I understand why of course: in a program which assumably uses an X-Y-Z co-ordinate system a 3-way balance is probably one of the hardest things to properly express. I know: I've tried.

The usual issue at least for me though is that the part is very touchy about whether it will or won't let you place parts on it. For instance: It will take the 3x symitry for SRBs, but not for some fuel tanks, and so on.

In the space plane hanger in particular: it simply won't allow you to use the 2x symitry to place the bottom 2 tanks as symmetrical parts.

In both, I've had issues with engines clipping into each other with the result being at best overheating, and at worst fiery kerbal death.

One fix I could think of would be to very slightly increase the distance between the attachment points on the bottom of the part, but not sure how that would effect the problem of balancing this out.

Anyone else experiencing these issues?