Hi Riku,
sorry, but according to my knowledge, you're wrong. Screenshot from SPPB 3.8.10 settings

"Top" position was never in v3.x. To be 100% sure, I checked SPPB v3.2.0 (2018), v3.6.0 (2019), v3.7.15 (2021) and v3.8.10 (2023) admin settings, so I base my opinion on the source files.
Maybe you've made a mistake in addon name, check Feature addon or Image Layouts addon, they have more options.
OR somebody edited/customized that addon code in the past, hmm? Right now, different addon must be used in SPPB 5.x, or customize your addon code (php / css).