How to run this ffmpeg command lines in hybrid？

[Selur]

I can't reproduce this here.
the original:

mediainfo.exe g:\Output\iId_2_aid_1_DELAY_-53ms_2023-02-08@15_48_34_7510_01.ac3
General
Complete name                            : g:\Output\iId_2_aid_1_DELAY_-53ms_2023-02-08@15_48_34_7510_01.ac3
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Commercial name                          : Dolby Digital
File size                                : 1.53 MiB
Duration                                 : 33 s 376 ms
Overall bit rate mode                    : Constant
Overall bit rate                         : 384 kb/s

Audio
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Commercial name                          : Dolby Digital
Duration                                 : 33 s 376 ms
Bit rate mode                            : Constant
Bit rate                                 : 384 kb/s
Channel(s)                               : 6 channels
Channel layout                           : L R C LFE Ls Rs
Sampling rate                            : 48.0 kHz
Frame rate                               : 31.250 FPS (1536 SPF)
Compression mode                         : Lossy
Stream size                              : 1.53 MiB (100%)
Service kind                             : Complete Main

converted to aac with 'tempo 0.80000000' gives:

mediainfo.exe g:\Output\iId_2_aid_1_ms_2023-02-08@15_48_34_7510_02.aac
General
Complete name                            : g:\Output\iId_2_aid_1_ms_2023-02-08@15_48_34_7510_02.aac
Format                                   : MPEG-4
Format profile                           : Base Media / Version 2
Codec ID                                 : mp42 (M4A /mp42/isom)
File size                                : 263 KiB
Duration                                 : 41 s 856 ms
Overall bit rate mode                    : Variable
Overall bit rate                         : 51.4 kb/s
Encoded date                             : UTC 2023-02-08 14:48:56
Tagged date                              : UTC 2023-02-08 14:48:58
FileExtension_Invalid                    : braw mov mp4 m4v m4a m4b m4p m4r 3ga 3gpa 3gpp 3gp 3gpp2 3g2 k3g jpm jpx mqv ismv isma ismt f4a f4b f4v

Audio
ID                                       : 1
Format                                   : AAC LC SBR
Format/Info                              : Advanced Audio Codec Low Complexity with Spectral Band Replication
Commercial name                          : HE-AAC
Format settings                          : Explicit
Codec ID                                 : mp4a-40-2
Duration                                 : 41 s 856 ms
Bit rate mode                            : Variable
Bit rate                                 : 50.3 kb/s
Maximum bit rate                         : 144 kb/s
Channel(s)                               : 6 channels
Channel layout                           : C L R Ls Rs LFE
Sampling rate                            : 48.0 kHz
Frame rate                               : 23.438 FPS (2048 SPF)
Compression mode                         : Lossy
Stream size                              : 257 KiB (98%)
Writing library                          : Nero AAC codec 1.5.4.0
Encoding settings                        : -br 128000
Encoded date                             : UTC 2023-02-08 14:48:56
Tagged date                              : UTC 2023-02-08 14:48:58

Audio length did change as expected.

Is your input by any change vfr?

Cu Selur