This worked I believe on rhel9.3 and prior so this may be a regression. It is odd that the math can no longer make the images fit on the available devices with the 80% FREE specified.

kernel-5.14.0-402.el9    BUILT: Thu Dec 21 10:30:03 PM CET 2023
lvm2-2.03.23-1.el9    BUILT: Tue Nov 28 02:15:42 PM CET 2023
lvm2-libs-2.03.23-1.el9    BUILT: Tue Nov 28 02:15:42 PM CET 2023


[root@grant-01 ~]# pvscan
  PV /dev/sda1   VG snapper_thinp   lvm2 [<2.00 GiB / <1.99 GiB free]
  PV /dev/sdb1   VG snapper_thinp   lvm2 [<2.00 GiB / <1.99 GiB free]
  PV /dev/sdd1   VG snapper_thinp   lvm2 [<2.00 GiB / <1.99 GiB free]
  PV /dev/sde1   VG snapper_thinp   lvm2 [<2.00 GiB / <1.99 GiB free]
  PV /dev/sdf1   VG snapper_thinp   lvm2 [<2.00 GiB / <2.00 GiB free]
  PV /dev/sdg1   VG snapper_thinp   lvm2 [<2.00 GiB / <2.00 GiB free]
  Total: 6 [<11.98 GiB] / in use: 6 [<11.98 GiB] / in no VG: 0 [0   ]
[root@grant-01 ~]# vgs
  VG            #PV #LV #SN Attr   VSize   VFree  
  snapper_thinp   6   1   0 wz--n- <11.98g <11.95g
[root@grant-01 ~]# lvs
  LV   VG            Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  meta snapper_thinp rwi-a-r--- 8.00m                                    100.00          
[root@grant-01 ~]# lvs -a -o +devices
  LV              VG            Attr       LSize Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert Devices                                                            
  meta            snapper_thinp rwi-a-r--- 8.00m                                    100.00           meta_rimage_0(0),meta_rimage_1(0),meta_rimage_2(0),meta_rimage_3(0)
  [meta_rimage_0] snapper_thinp iwi-aor--- 4.00m                                                     /dev/sda1(1)                                                       
  [meta_rimage_1] snapper_thinp iwi-aor--- 4.00m                                                     /dev/sdb1(1)                                                       
  [meta_rimage_2] snapper_thinp iwi-aor--- 4.00m                                                     /dev/sdd1(1)                                                       
  [meta_rimage_3] snapper_thinp iwi-aor--- 4.00m                                                     /dev/sde1(1)                                                       
  [meta_rmeta_0]  snapper_thinp ewi-aor--- 4.00m                                                     /dev/sda1(0)                                                       
  [meta_rmeta_1]  snapper_thinp ewi-aor--- 4.00m                                                     /dev/sdb1(0)                                                       
  [meta_rmeta_2]  snapper_thinp ewi-aor--- 4.00m                                                     /dev/sdd1(0)                                                       
  [meta_rmeta_3]  snapper_thinp ewi-aor--- 4.00m                                                     /dev/sde1(0)                                                       
 
[root@grant-01 ~]# lvcreate --yes  --type raid10 -m 1 -i 2 -l+80%FREE -n 80_percent snapper_thinp
  Using default stripesize 64.00 KiB.
  Rounding size <4.78 GiB (1223 extents) up to stripe boundary size 4.78 GiB (1224 extents).
  Consider pruning snapper_thinp VG archive with more then 421 MiB in 5161 files (see archiving settings in lvm.conf).
  LV snapper_thinp/80_percent_rimage_2 using PV /dev/sdf1 is not redundant.
  Insufficient suitable allocatable extents for logical volume snapper_thinp/80_percent
  Consider pruning snapper_thinp VG archive with more then 421 MiB in 5162 files (see archiving settings in lvm.conf).
 
[root@grant-01 ~]# lvcreate --yes  --type raid10 -m 1 -i 2 -l+70%FREE -n 80_percent snapper_thinp
  Using default stripesize 64.00 KiB.
  Consider pruning snapper_thinp VG archive with more then 421 MiB in 5166 files (see archiving settings in lvm.conf).
  LV snapper_thinp/80_percent_rimage_2 using PV /dev/sdf1 is not redundant.
  Insufficient suitable allocatable extents for logical volume snapper_thinp/80_percent
  Consider pruning snapper_thinp VG archive with more then 421 MiB in 5167 files (see archiving settings in lvm.conf).
 
[root@grant-01 ~]# lvcreate --yes  --type raid10 -m 1 -i 2 -l+65%FREE -n 80_percent snapper_thinp
  Using default stripesize 64.00 KiB.
  Rounding size <3.88 GiB (993 extents) up to stripe boundary size 3.88 GiB (994 extents).
  Consider pruning snapper_thinp VG archive with more then 421 MiB in 5168 files (see archiving settings in lvm.conf).
  Consider pruning snapper_thinp VG archive with more then 421 MiB in 5169 files (see archiving settings in lvm.conf).
  Logical volume "80_percent" created.