LZMA filtering documentation very poor

I'm trying to optimise compressing some documents, so I'm using LZMA's filters. These are really badly documented: https://docs.python.org/3/library/lzma.html#filter-chain-specs

General problems:

• The filters are using short-hand for variable names lc, lp, mf, which is really bad practice for a publically available interface (and even for internal ones!). (ok, so this isn't a doc problem, but a library one).
• It's not at all clear what any of the variables do. There's no links to any documentation (even third-party) which explain what any of these things do.
• It's not clear what values are acceptable for some of them.
• • preset is documented elsewhere, and I assume the value range is the same?
• • lc doesn't say the maximum is 4, you have to read lp to see the combined maximum is 4, and then deduce.
• • lc, lp, pc, nice_len, don't state minimums
• No defaults stated other than depth (0),
• It's not at all clear what the different Filters do.
• The limited blurb that does exist about Filter chains seems to assume a high degree of expertise in these things. For example: The last filter in the chain must be a compression filter, and any other filters must be delta or BCJ filters. - that has cleared nothing up.
• What's a MODE_FAST or MODE_NORMAL do?
• What's the difference between MF_HC3, MF_HC4, MF_BT2, MF_BT3, or MF_BT4?
• What does lzma.PRESET_EXTREME do? There's no documentation for lzma.PRESET_DEFAULT at all (which my IDE exposed to me via autocomplete).

Etc etc.

Some specific problems as well:

• 'filters': [{'id': 33, 'preset': 6, 'dict_size': 262144, 'lc': 1, 'lp': 1, 'mode': 2, 'nice_len': 1, 'mf': 3}]
  That creates an LZMAError. It's only after generating thousands of combinations of these that I notice a pattern: nice_len: 1. It seems there's a minimum nice_len size. This is not documented.

• 'filters': [{'id': 33, 'preset': 2147483653, 'dict_size': 1073741824, 'lc': 1, 'lp': 0, 'mode': 2, 'nice_len': 201, 'mf': 20}]
  Generates a MemoryError (as do lots of others of my tests). No idea why as I have plenty of RAM. I presume some combination of those settings are causing an issue, but there's no documentation warning about this.

從連結的 Python 文件頁面中的 LZMA 篩選器鏈規格區段開始，檢視篩選器選項、預設集、模式和篩選器鏈的說明。記錄參數的意義、有效範圍、預設值、篩選器之間的差異，以及相關的錯誤或記憶體限制，以便說明範例和失敗情況。