BTRFS Alterantive status suggestion:

Legend:
Tag
Description
Stability
[0]
OK , no known bugs or defiencies
[1]
OK mostly , safe to use, but some non fatal bugs are known
[2]
RISKY, no fatal bugs known , but this feature is new and not well tested
[3] ... [99]
Reserved for future use
[X]
UNSTABLE, unsafe to use - known bugs
Other tags
[P]
Slow performance
[L]
Layering problem


Feature
4.14 LTS
4.19 LTS
5.4 LTS
5.5 (current)
Notes
Magic feature X
[X]
[1]
[0] [0]
See #1
Super feature Y
[2][P]
[1][P]
[0][P]
[2]
See #2
Amazing function Z
[2][L]
[X]
[0]
[0]
See #3








Notes:
1)
The magic feature...
* Was not so magic in 4.14-4.15 because it ate your data
* does work better in 4.16 but could cause random hangs
* was fixed in kernel 4.17

2)
The super feature...
* has been super all the time,
* It is dead slow on ARM , but was better in 5.2
* in 5.3 it is ok for x86 but still a bit slow on ARM
* Has a speed fix in the current kernel , who knows how that may turn out...

3)
The amazing function...
* was great unless layered on top of LVM
* sadly was affected by a nasty bugbite in kernel 4.13 - 5.2 (inclusive)
* got self-aware in kernel 5.3 and may take over the world soon