I think you guys are missing an opportunity here. The Twiddler excels at driving a much-used application with command keys. Rather than wrestle with complex thumbkey chords for command keys, why not define your own special purpose command chords? I find this a better use of spare chords than mapping them to common ngrams.
If the commands have some (even remotely) spatial relationship you can work out a set of chords that reflect that. As a small example, the configuration I use maps Find Again (<F3>) and Find Again Backwards (<Shift><F3></Shift>) as follows, allowing me to step back and forth through the matches (and exit Find) with just my middle finger:
0 MRMM = <F3>
0 MLMM = <Shift><F3></Shift>
0 MMMM = <Esc>
The relationship can be quite tenuous, as long as it makes sense to you. I hold my Twiddler horizontally so R maps naturally to down and L to up.
I found this approach so useful for cursor control that I based the configuration around it. The ??M? button (mapped to the space key) defines cursor mode, so:
0 M0M0 = <Left>
0 0MM0 = <Right>
0 L0M0 = <Up>
0 R0M0 = <Down>
0 LLM0 = <PageUp>
0 RRM0 = <PageDown>
0 LMM0 = <Home>
0 RMM0 = <End>
The pinky buttons are not involved in this, allowing ???R to add <Ctrl>, ???L to add <Shift> and ???M to add <Ctrl><Shift>. By using up some fast 2 button chords this has a slight impact on the speed of alphabetic chording, but it is well worth it. Suddenly the Twiddler's mousing limitations are irrelevant to text editing.
In fact I reserve the pinky buttons for Shift and Control with alphabetic chords as well, which has a more significant impact but comes in pretty handy for capitalization and the common editing control codes (with judicious mapping of the relevant characters):
0 RRR0 = c
0 MRR0 = v
0 LRR0 = x
0 RR00 = s
0 M0R0 = z
0 L0R0 = f
You may have guessed I am not a big fan of thumbkeys.