Yes. I think codec remapping already described in manual? You can add this termux-specific example into Termux (sub) section:
# apply at init decode
loglevel=fatal
formatprobesize=5000000
scan_all_pmts=1
remap_video_decoder libaom-av1=libdav1d
remap_video_decoder vp9=vp9_mediacodec
remap_video_decoder hevc=hevc_mediacodec
I also made av1 encoding profile, but as turned out this SoC can only DEcode small (512 pix max!) av1s, not encode them.
I do not see much of activity on reddit's r/termux or l.o.r forum with my request for testing, so I guess for now there is just me testing this.