Attaching mesh-switched parts with EVA construction cause Kraken events

[gotmachine]

Setup :

• KSP 1.12.3
• B9PS 2.20.0
• NearFutureConstruction 1.3.1

Reproduction steps :

• Create a sandbox game
• In the VAB, place a MK1-3 pod
• Grab a NF truss, for example the "Cubic family large truss"
• Switch it to a non-default subtype, for example "planar" (might not be necessary, see notes)
• Place it into the MK1-3 pod inventory
• Make sure you have an engineer in the pod, launch
• F12 cheat the craft into Kerbin orbit
• EVA with the engineer
• Go into EVA construction mode
• Grab the truss, surface-attach it on the pod
• The pod should be getting a kraken-level force kick upon placement

Note that reproducing can take a few tries, it doesn't always happen. And while it seems more frequent when the part is switched to a non-default subtype, it's also occasionally reproducible with the default subtype.

Excerpt from log entries when this happen :

[LOG 13:58:13.246] Event Weld Started not assigned to state Ladder (Idle)
[LOG 13:58:13.248] [Part truss-micro-02] [ModuleB9PartSwitch 'meshSwitch'] Switched subtype to Triangular
[LOG 13:58:13.281] DragCubeSystem: Creating drag cubes for part 'truss-micro-02'

I haven't done extensive testing or investigations, so I can't really offer much hindsight. While this seems something related to collider/rigidbody interactions, this could maybe have something to do with mass switching, hard to say.

As shown in this video, some parts also seem to be instantiated with all models active at once. I didn't reproduce that, but I got confirmation of this by some users.