Marked Theme In An Existential Clause

No great and enduring volume can ever be written on the flea, though many there be who have tried it.

 — Herman Melville

No great and enduring volume can ever be written on the flea	though many there be	who have tried it
α	x β
	α	= β

though	many	there	be
	Existent		Process: existential
Theme: marked		Rheme
	Complement	Subject	Finite	Predicator

Note that the Subject is not "unmarked Theme".

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.