Scoring Central

I just came across this site, which includes an index of instruments in SFZ format: https://sfzinstruments.github.io/

Pianos (Kontakt, SFZ, EXS24)

Drums and Percs (Kontakt, SFZ, EXS24)

Percs, Choir & Music Box (Kontakt Player)

Music Box (Konatkt)

Melodica (Kontakt)

Taikos (Kontakt)

Duduk (Kontakt)

Xiao Flute (Kontakt)

Pipe Organ (Kontakt)

Drums (Kontakt, Open)

Sound Design SFX (Kontakt)

Sound Design - Guitar SFX (Kontakt)

Orchestral Risers (Kontakt)

Trailer SFX and Trailer Percs (Wav, Kontakt and Kontakt Player)

Ferrum is top-notch freebie for Trailer percs and is compatible with the free Kontakt Player. Their download manager gets flagged as malicious by Windows for some reason but you can request a direct download link from them.

Rest all are trailer transition SFX like risers, downers and pulses.