SIP_ETSI broken with Titan 11

I managed to wrangle the code into a form that compiles:

git clone https://gitlab.eclipse.org/eclipse/titan/titan.misc.git
wget https://gitlab.eclipse.org/-/project/179/uploads/bff9610aeda197cc4677309778c518d9/submodules.patch
wget https://gitlab.eclipse.org/-/project/179/uploads/5f155d060da482d9d3b8182778a4dd97/steps11.patch
cd titan.misc
# TODO: Send the patch upstream: https://gitlab.eclipse.org/eclipse/titan/titan.misc/-/issues/25
git apply ../submodules.patch
cd SIP_ETSI
git commit -a -m "Update submodules"
git submodule update --init --remote TestPorts/SIPmsg/ Libraries/TCCUsefulFunctions/
./install.script
make XMLDIR=$XMLDIR CXXFLAGS='-Wall -ggdb'
# TODO: Figure out why the compiler is producing wrong code: https://gitlab.eclipse.org/eclipse/titan/titan.misc/-/issues/26
git apply ../../steps11.patch
make XMLDIR=$XMLDIR EXECUTABLE=SIP_MainModule CXXFLAGS='-Wall -ggdb'

However, the test suite still crashes:

$ ttcn3_start ./SIP_MainModule 
ttcn3_start: Starting the test suite
ttcn3_start: warning: no configuration file was specified or the file name was misspelled
spawn /nix/store/va7whfjsrisgmpl0mxgx2g5g2mgl70zw-titan-core-11.0.0/bin/mctr_cli

*************************************************************************
* TTCN-3 Test Executor - Main Controller 2                              *
* Version: 11.0.0                                                       *
* Copyright (c) 2000-2024 Ericsson Telecom AB                           *
* All rights reserved. This program and the accompanying materials      *
* are made available under the terms of the Eclipse Public License v2.0 *
* which accompanies this distribution, and is available at              *
* https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html            *
*************************************************************************

MC@sy: Unix server socket created successfully.
MC@sy: Listening on TCP port 34359.
MC2> sy is the default
spawn ././SIP_MainModule sy 34359
TTCN-3 Host Controller (parallel mode), version 11.0.0
MC@sy: New HC connected from 127.0.0.1 [127.0.0.1]. sy: Linux 6.12.9 on x86_64.
cmtc
MC@sy: Downloading configuration file to all HCs.
HC@sy: SIP_Templates.ttcn:94: Dynamic test case error: Assignment of an unbound charstring value to a template.
Error: There were errors during configuring HCs.
Error during initialization. Cannot create MTC.
MC2> ttcn3_start: error: the MTC cannot be created. 
exit
MC@sy: Shutting down session.
MC@sy: Shutdown complete.

steps11.patch submodules.patch