United Plugins has JMG Sound's Mirror and they are calling it the first "reverse negative delay" plug-in. Mono or stereo audio is recorded into a buffer then it is played back in reverse. By looking ahead in time of the "play head" in your DAW, you'll have your dry audio (in any blend) along with reverb mixed together as backwards audio.

I used Mirror in a Pro Tools session on a big-sounding drum loop but first I had to set the Time parameter for the 1/4 buffer size to temporarily store the audio to be reversed. This worked fine for my loop that is right on the grid at 75 BPM. On the same song, the main acoustic guitar's finger picking part sounded awesome reversed with a little backwards reverb.

There are separate Wet and Dry controls as well as the Verb control that sets the level of reversed reverb. The Trim control mellows out errant transients (attacks) at the end of reversed audio while the Blur controls a wet/dry mix of a shorter reverb to smooth things out more. Mirror includes both a 20Hz to 2kHz high pass and a 200Hz to 20kHz low pass filters that affect the reversed audio only.

I used Mirror without Negative delay and there is no latency and the reversed audio plays right after the original dry like any reverb. If you want the reversed reverb to play from the start, use Negative delay if your system has enough delay compensation or just record it beforehand and slide it into sync.

I used Mirror on drums guitar tracks, reverb returns, even bass tracks and I found plenty of subtle uses for choirs and keyboard pads.

JMG Sound's Mirror is available as AAX, AU, VST, and VST3 plug-in that's downloadable for a time-limited introductory of €22 EUR with regular price at €69.

https://unitedplugins.com/mirror/