[BUG] Saltclass can't reuse variable which have type list or dict

Description
I used to use reclass (http://reclass.pantsfullofunix.net/) for pillar data.
Now I use its fork https://github.com/salt-formulas/reclass because it was rewritten on python3.

I want to replace reclass with saltclass because it has interesting features which I need.
But I encountered problems while testing saltclass.
Saltclass can't expand pillar value that is not of type 'str'. I tried to use yaml possibilities to reuse variables.

And I can see from these issues that they have existed since 2018.
https://github.com/saltstack/salt/issues/50262
https://github.com/saltstack/salt/issues/61934
https://github.com/saltstack/salt/pull/52407

Given this, I have following questions:

1. Will you remove saltclass in the feature from the Core Modules / Supported Modules? Maybe you want to remove it completely and therefore do not solve this problem.
2. Could you advise me how I can reuse pillar variables using saltclass? Maybe there is a way to do this using jinja.
3. When you will solve problem with expanding pillar value that is not of type 'str'?

Setup

Example pillar data
cat nodes/server01.test.local.yml

environment: base
states:
pillars:
  test:
    S1: "Test S1"

    S2: ${test:S1}

    L1:
      - "item1"
      - "item2"
      - "item3"

    L2: ${test:L1}

    D1:
      D1_item1: item1
      D1_item2: item2

    D2: ${test:D1}

Steps to Reproduce the behavior
After this command
salt "server01.test.local" saltutil.refresh_pillar

I can see following errors in the /var/log/master file

[CRITICAL][2219096] Pillar render error: Failed to load ext_pillar saltclass: replace() argument 2 must be str, not list 
or 
[CRITICAL][2355663] Pillar render error: Failed to load ext_pillar saltclass: replace() argument 2 must be str, not dict

1 Call salt -v "server01.test.local" pillar.get test:S2
It works as expected.
Output:

server01.test.local:
    ----------
    test:S2:
        Test S1

2 Call salt -v "server01.test.local" pillar.get test:L2
Output:

server01.test.local:
    ----------
    test:L2:
        ${test:L1}

3 Call salt -v "server01.test.local" pillar.get test:D2
Output:

server01.test.local:
    ----------
    test:D2:
        ${test:D1}

Versions Report

Salt Version:
          Salt: 3007.1
 
Python Version:
        Python: 3.10.14 (main, Apr  3 2024, 21:30:09) [GCC 11.2.0]
 
Dependency Versions:
          cffi: 1.16.0
      cherrypy: unknown
      dateutil: 2.8.2
     docker-py: 7.1.0
         gitdb: Not Installed
     gitpython: Not Installed
        Jinja2: 3.1.4
       libgit2: Not Installed
  looseversion: 1.3.0
      M2Crypto: Not Installed
          Mako: Not Installed
       msgpack: 1.0.7
  msgpack-pure: Not Installed
  mysql-python: Not Installed
     packaging: 23.1
     pycparser: 2.21
      pycrypto: Not Installed
  pycryptodome: 3.19.1
        pygit2: Not Installed
  python-gnupg: 0.5.2
        PyYAML: 6.0.1
         PyZMQ: 25.1.2
        relenv: 0.16.0
         smmap: Not Installed
       timelib: 0.3.0
       Tornado: 6.3.3
           ZMQ: 4.3.4
 
Salt Extensions:
 saltext.vault: 1.0.0
 
Salt Package Information:
  Package Type: onedir
 
System Versions:
          dist: ubuntu 20.04.6 focal
        locale: utf-8
       machine: x86_64
       release: 5.4.0-162-generic
        system: Linux
       version: Ubuntu 20.04.6 focal

Start with the saltclass ext_pillar path referenced by the error, then reproduce the example using saltutil.refresh_pillar and inspect the results with pillar.get. Done means list and dict pillar references expand without the reported type errors while the existing string reference continues to work.