It depends.
Dolby suggests discarding the LFE channel when there is no sub-woofer for headroom reasons.
(The LFE channel has 10dB more headroom than the screen channels, so you're looking for reference level SPLs of up to 115dB SPL at the seats which becomes 120dB at the speakers accounting for propagation loss. With a 90dB efficient speaker that'll take a 1000W amplifier and more displacement than most speakers are capable of).
Dolby suggests discarding the LFE channel when there is no sub-woofer for headroom reasons.
(The LFE channel has 10dB more headroom than the screen channels, so you're looking for reference level SPLs of up to 115dB SPL at the seats which becomes 120dB at the speakers accounting for propagation loss. With a 90dB efficient speaker that'll take a 1000W amplifier and more displacement than most speakers are capable of).