'As Usual' vs 'Usually'

as usual serves as a comment Adjunct of the type 'predictable'.

See Halliday & Matthiessen (2014: 191).

'Lead' As Circumstantial Identifying Process

An Enclosed Structurally Unrelated Clause

Mr Minter, 'Call me Ted', was  a large, untidy, perpetually smiling man with the look of an astute rabbit.

— John Mortimer Rumpole And The Asylum Seekers

One way to analyse the enclosed clause as structurally related is to take the view from below. Because it is realised as its own tone group (TONALITY) and realised by tone concord with what precedes (TONE), the enclosed clause is realised as if it were in non-defining elaborating relationship with the surrounding clause. Such an interpretation, though, requires treating the clause that projected it as ellipsed.

Stylistic Metaphor

Emotion-Imbued Cognitive Projection

I am unable to look at my customer in the dock	without feeling	there but for the Grace of God goes Horace Rumpole
α	+ β
	1	' 2

I	am unable to look	at my customer in the dock
Behaver	Process: behavioural	Location: orientation

without	feeling
	Process: mental: cognition

there	but for the Grace of God	goes		Horace Rumpole
Theme: marked	Rheme
Location	Contingency: default	Process: material		Actor
Attribute: circumstantial		Process: relational		Carrier
Adjunct	Adjunct	Predicator	Finite	Subject
Residue			Mood

The above analysis assumes the Mood Tag would be doesn't he (rather than doesn't there).
This analysis is supported by the phonological salience of there.