The Deferred Lightning option literally max out my integrated Graphic to the max, giving my laptop a unstable 30 fps and LESS . While java shader can run "well" at 30 fps.

Modèle: HP 17-inch cp007ca laptop
Processeur: AMD Ryzen 3 5300u avec Graphique intégré Radeon
Carte graphique intégrée: APU AMD Radeon(TM) Graphics, VRAM 512 MB DDR4 MHz
Mémoire RAM: 12 go (11,3 go utilisable)

How to reproduce:
1. Install the latest Minecraft preview on a low-end or mid end laptop with integrated graphic
2. Download a PBR shader pack like "Vanilla PBR"
3. Activate the Render Dragon Feature for Creators toggle
4. Activate the texture pack in the world
5. Launch the world
6. Look at the fps counter it will be very low like 20 fps or even 1-10 fps on as 4k output to my tv.
7. (optional) : run task manager and look at the performance tab specially the GPU part.