मन्त्र रामायण (नीलकण्ठ चतुर्धर - पं. रामकुमार राय सविस्तार हिन्दी व्याख्या सटीक)

कारणरूपेण'.
Let's look at the character: is it 'स्थू'?
Yes, 'स्थूलसूक्ष्मकारण' is the standard Vedantic terminology (स्थूल, सूक्ष्म, कारण शरीर/उपाधि). It is definitely 'स्थूल'!

Let's check L23:
"त्रयः पितरस्तदभिमानिनश्चिदाभासाः वैश्वानरहिरण्यगर्भान्तर्यामिसंज्ञाः । तज्ज्रो"
Wait, is that 'तज्जो' or 'तज्ज्रो'?
Look at the word after 'संज्ञाः ।':
'त' 'ज्जो' -> is there a repha or r-stroke?
Wait, 'तज्जः' (तस्मात् जातः) -> 'तज्जो' or 'तज्ज्ञो'?
Wait! 'तज्ज्रो' or 'तज्ज्ञो' or 'तज्जो'?
Wait, the next word is: 'विज्ञानधातुरपि'!
Could it be 'तज्जो विज्ञानधातुरपि' (born from that)?
Look at the letter: 'त', then double 'ज' with 'ो' = 'तज्जो'?
Wait, does it have an '्' under it? It has 'ज्' + 'ज' + 'ो' = 'तज्जो'.
Wait, why would it be 'तज्जो'? Because from the causal/macrocosmic comes the microcosmic: "तज्जः विज्ञानधातुः अपि"!
Wait, or