Vaheguru Ji Ka Khalsa Vaheguru Ji Ki Fateh!!
Of course markers are not to be pronounced. Haddan is STOP, we don't say haddan. Shabad Numbers are markers to give the count of Shabads, we don't pronounce them. Rahau tells to PAUSE.
1. But don't you think here we are confusing markers with Lagaan (Vowels) or is it being said deliberately?
2. What's your source of calling markers to 10 Lagaan?
You can check Patiala University's website, they are not markers but vowels:
http://www.learnpunjabi.org/intro1.asp
Kabit Bhai Gurdas Ji:
ਸਿੰਮ੍ਰਿਤਿ ਪੁਰਾਨ ਕੋਟਾਨਿ ਬਖਾਨ ਬਹੁ ਭਾਗਵਤ ਬੇਦ ਬਿਆਕਰਨ ਗੀਤਾ ।
If all the 31 Simrities, 18 Purans, Bhagvad Geeta, four Vedas and their grammar become millions and speak,
ਸੇਸ ਮਰਜੇਸ ਅਖਲੇਸ ਸੁਰ ਮਹੇਸ ਮੁਨ ਜਗਤੁ ਅਰ ਭਗਤਿ ਸੁਰ ਨਰ ਅਤੀਤਾ।
If Shesh Nag of thousands of tongues, Dharamraj, Kuber and other gods, Shiva and hermits and saints of the whole world, noble men get together in millions and speak;
ਗਿਆਨ ਅਰ ਧਿਆਨ ਉਨਮਾਨ ਉਨਮਨ ਉਕਤਿ ਰਾਗ ਨਾਦਿ ਦਿਜ ਸੁਰਮਤਿ ਨੀਤਾ।
If seekers of many type of knowledge, contemplations and wise men who discuss various subjects, people of higher spiritual state, who can speak about various skills, all the Ragas and their seven notes, various knowledgeable scholars like Vashisht, goddess Saraswati keep prasing everyday the glory of Guru Ji's Shabad Gurbani,
ਅਰਧ ਲਗ ਮਾਤ੍ਰ ਗੁਰਸਬਦ ਅਖਰ ਮੇਕ ਅਗਮ ਅਤਿ ਅਗਮ ਅਗਾਧਿ ਮੀਤਾ ॥੫੪੦॥
O friend! all the above will fall woefully short of saying the praise of a (ਅਰਧ ਲਗ ਮਾਤ੍ਰ) half a Vowel of (ਗੁਰਸਬਦ) Gurbani Ji. The significance of Guru's words is beyond the extent of all knowledge.
Who are we or Prof. Sahib Singh to say that (ਲਗ ਮਾਤ੍ਰ) Lagaan of Gurbani are insignificant and are there only to describe grammar?
and in future, Scholars like you Giani Ji would even suggest to eliminate them from Gurbani as you are already pointing towards it in your post above.
