Earlier saw tweets saying there's no Hindus attempt to understand Islam pre 18th cent.

It's true, explicit reference to Islam is almost absent in Sanskrit texts but there's enough in vernacular to argue against the assertion.
Especially in writings of Sant Eknath.

Eknath came from a family of Sanskrit Pandits, he wrote in Marathi. He saw in his time the defeat of Vijaynagar and the massive depression that it must have caused among Hindus. He realized something needed to be done to inspire them.
And what was this something?
Shri Rama.

And he was so obsessed with the idea that he thought it was Shri Rama himself who was urging him to do this. Kind of similar to Tulasidas here.

He had also experienced the hostility of turkas personally. They had spit on him more than once publicly.
However, he was careful to not get too explicit in his attack on Turkas and instead attack them through metaphors in his Bhavaratha Ramayana.

Here, he talks of our gods being in horrible conditions : Indra in service of Ravana, Agni washing Ravana's clothes. Here he was alluding to the fact that many respectable Hindus had been reduced to sorry state under the M rule.

It becomes clearer that the message is very political right from the start of his Ramayana.

Here Kaushalya Ji gets in the warrior mode during her pregnancy when her Dashrath Ji mentions Ravana

Eknath has been often called Tulasi of Maharashtra but his Bhavarth Ramayan is much more consciously political than Ramcharitmanas.

He purpose it to exhort people to remove the Ravanas of that time and establish Ramrajya.

Another politically loaded message here. We should also remember Eknath was not merely writing. he also used to travel around singing this stuff. Imagine, the effect it would have had on the people.

It's suggested Guru Ramdas built on the legacy of sant Eknath.

He too wrote two Ramayanas, one short and another long but his Ramayanas were even more political as he wrote only SundarKanda and Yudhakanda, the portions where Shri Rama fights the actual battle.

So, thus far we see use of symbols
1. Build unity among Hindus
2. To demonize the Turkas by comparing them to demons of the epic.
3. Suggest a course of action citing examples of our gods.

However,in addition to these attacks using metaphors, he also attacked them explicitly

This can be seen in his work 'Hindu-Turk Samvad' which presents an argument between a Hindu and Turka, both trying to establish superiority of their religions.

Turka : hey k@feer !
H : Shoo! don't p0llushan me !

More of that amazing conversation. The M like the ones of current time attacks on all expected areas : God has form, Krishna thief, why you bathe in river, murti puja etc.

If you think Chad Hindu will get rattled by that response, you are wrong ! He comes out all guns blazing !

If God is everywhere, why not in idols/ prisons?
Why do you have to make effort to kunvurt?
Gad's was mistaken to make us H ?

Though after all this heavy firing, Eknath Ji Mahraaj makes it end very amicably with sweet words like God is one and all we need is love etc.

You have made your point, why get in trouble with 'authorities' ? Right ?

The point here is that Sant Eknath shows great clarity about Islam and its tenets. And he ready with both attack and defence.
I point this out because some people blow the lack of Hindu intellectual response to Islam totally out of proportion. +

I mean there are H who get all nervous even today if someone attacks murti puja and here's someone in 16th century hitting it out of the park !

I stress again, this is not a person who writes and book and sleeps, he actually wanders around redpilling people with that writing!

And there's no reason to believe that Eknath was one of his kind. Besides, I also think that there is some circumstantial evidence in favor of Hindus in the happenings of Akbar's Ibadatkhana.
I don't know if there are records of the discussions that were held there +

And I don't know know what kind of statements were the Brahmins making there but if seeing what happened to Akbar in last years of his life, I think must have done well.

That said, we should have prepared more material against the mlechh@s

But imo there were some possible reasons that might have limited the production of such output.

1. The circumstances were not conducive to such pursuits. Though some geographies which were free, such as Vijaynagar, for a long time, could have done it.

2.Which makes me think that they just didn't think that the mlechhas were worthy of their response. That'd be a very emotional response for scholars but I can understand that.

3. We are ancient people with sophisticated communication skills. We love to talk in symbols and metaphors.
Plus, of course it's less risky.
Remember, what Tilak was doing 300 years after Sant Eknath? He was telling similar stories : Shivaji vs Afzal Khan etc.

4. Unlike the time of Buddhists, we had lost power in large parts. We were not trying to impress the kings with our arguments, we had to get the masses with us. The messaging had to be short, sweet and simple.

5. Sometimes, a class or group of people consciously choose a certain role and once that is chosen as the primary role, they ignore everything else even if it was not impossible to do. Take Sanghis for instance, they decided we have to do 'Sangathan' +

And they ignored all padhai likhai. Probably the ideal in medieval period was to go in the field and ' do things' rather than building logical arguments.

Anyway, I think Sant Eknath's case clearly shows that we had enough firepower to take on the turkas in a debate.

The thing as that were not the debating kind. That said, possibly much more material from the period in other languages. I am sure ancestors had understood them very well.

Source :
1. Eknath's treatment of the Ramayana as a socio political metaphor : SG Tulpule in
2. Eknath (book) : G V Tagare
3. Defining Hinduism : J. E. Llewellyn

1. 1. Eknath's treatment of the Ramayana as a socio political metaphor (chapter) : SG Tulpule in Ramayana And Ramayanas by Monica Theil Horstmann