The heat shield is just another regular shield and doesn't offer any inflating stuff.
The service module doesn't release the MK1-2 pod. It's options doesn't contain any "Decouple" item and when used in VAB it doesn't generate any staging step.

The inflatable floatation collar is dependent on the Klockheed Martian Special Parts plugin, which unfortunately is no longer being maintained. I haven't been able to find a replacement plugin to support the aforementioned feature, either.

As you probably realised, the Service Module requires @Starwaster's AnimatedDecouplers plugin, which was listed quite clearly as a dependency in the forum threads and README.

Nevermind.... must be some dependency that were missing.