Testing waveshare-rp2350-lcd-1.28 and only found the following under boards: waveshare_rp2350_lcd_1. The code would not compile as it cut off the .28 and could not find a file named waveshare_rp2350_lcd_1 as stored in PICO_BOARD.
I updated the filename in the sdk, changing the period to an underscore, reloaded the project and was able to successfully compile.
There are several headers with a period in the file name and all of them show up in the boards list cut off at the period, so I assume they would all have the same issue.
waveshare_rp2040_lcd_0.96.h
waveshare_rp2040_lcd_1.28.h
waveshare_rp2040_touch_lcd_1.28.h
waveshare_rp2350_lcd_0.96.h
waveshare_rp2350_lcd_1.28.h
waveshare_rp2350_touch_lcd_1.28.h