Following a hint from the dev team I gave the gl4es wrapper a try. Instructions for installation can be found here.
The wrapper seems to work with the Python Kivy toolkit, which uses SDL2 as graphical backend. My application is not lightning fast, but much speedier than before and probably fast enough for my purposes.
These are the log messages I get to see now when starting my Kivy application after the installation of gl2es:
LIBGL: Initialising gl4es
LIBGL: v1.1.5 built on Jan 19 2024 16:01:03
LIBGL: Using GLES 2.0 backend
LIBGL: loaded: libGLESv2.so
LIBGL: loaded: libEGL.so
LIBGL: Using GLES 2.0 backend
arm_release_ver of this libmali is 'g2p0-01eac0', rk_so_ver is '4'.
LIBGL: Hardware Full NPOT detected and used
LIBGL: Extension GL_EXT_blend_minmax detected and used
LIBGL: FBO are in core, and so used
LIBGL: PointSprite are in core, and so used
LIBGL: CubeMap are in core, and so used
LIBGL: BlendColor is in core, and so used
LIBGL: Blend Subtract is in core, and so used
LIBGL: Blend Function and Equation Separation is in core, and so used
LIBGL: Texture Mirrored Repeat is in core, and so used
LIBGL: Extension GL_OES_mapbuffer detected
LIBGL: Extension GL_OES_element_index_uint detected and used
LIBGL: Extension GL_OES_packed_depth_stencil detected and used
LIBGL: Extension GL_OES_depth24 detected and used
LIBGL: Extension GL_OES_rgb8_rgba8 detected and used
LIBGL: Extension GL_EXT_texture_format_BGRA8888 detected and used
LIBGL: Extension GL_OES_depth_texture detected and used
LIBGL: Extension GL_OES_texture_stencil8 detected and used
LIBGL: Extension GL_EXT_texture_rg detected and used
LIBGL: Extension GL_EXT_color_buffer_float detected and used
LIBGL: Extension GL_EXT_color_buffer_half_float detected and used
LIBGL: high precision float in fragment shader available and used
LIBGL: Max vertex attrib: 16
LIBGL: Extension GL_OES_standard_derivatives detected and used
LIBGL: Extension GL_ARM_shader_framebuffer_fetch detected and used
LIBGL: Extension GL_OES_get_program_binary detected and used
LIBGL: Number of supported Program Binary Format: 1
LIBGL: Max texture size: 16383
LIBGL: Max Varying Vector: 31
LIBGL: Texture Units: 16/16 (hardware: 16), Max lights: 8, Max planes: 6
LIBGL: Extension GL_EXT_texture_filter_anisotropic detected and used
LIBGL: Max Anisotropic filtering: 16
LIBGL: Max Color Attachments: 1 / Draw buffers: 1
LIBGL: Hardware vendor is ARM
LIBGL: sRGB surface supported
LIBGL: EGLImage from Pixmap supported
LIBGL: EGLImage to Texture2D supported
LIBGL: EGLImage to RenderBuffer supported
LIBGL: Targeting OpenGL 2.1
LIBGL: Not trying to batch small subsequent glDrawXXXX
LIBGL: try to use VBO
LIBGL: glXMakeCurrent FBO workaround enabled
LIBGL: FBO workaround for using binded texture enabled
LIBGL: Force texture for Attachment color0 on FBO
LIBGL: Hack to trigger a SwapBuffers when a Full Framebuffer Blit on default FBO is done
LIBGL: glX Will try to recycle EGL Surface
LIBGL: Current folder is:/home/radxa
LIBGL: Loaded a PSA with 1 Precompiled Programs
arm_release_ver of this libmali is 'g2p0-01eac0', rk_so_ver is '4'.
[INFO ] [GL ] Using the "OpenGL" graphics system
[INFO ] [GL ] Backend used <sdl2>
[INFO ] [GL ] OpenGL version <b'2.1 gl4es wrapper 1.1.5'>
[INFO ] [GL ] OpenGL vendor <b'ptitSeb'>
[INFO ] [GL ] OpenGL renderer <b'GL4ES wrapper'>
[INFO ] [GL ] OpenGL parsed version: 2, 1
[INFO ] [GL ] Shading version <b'1.20 via gl4es'>
[INFO ] [GL ] Texture max size <16383>
[INFO ] [GL ] Texture max units <16>
So, if you are application uses SDL2, libGL or any wrapper around libGL, gl4es may do the trick for you.