What most of those people on Σχολη do, who are a little adept at writing, and want to encourage others is to try to engage you in conversation. This can be done in chat or via private message. People like to talk about themselves. Who are you? Where do you live? How many children do you have? Early on, someone only needs to answer in phrases. I would say that this type of banter is something that someone who is in their 1st quarter of Greek can answer. One thing needs to be understood: If you make a post or try to answer something in Greek, and make mistakes (misspell, use a word that is not in quite the right domain, etc.) no one is going to write you a message and say "Hey, you spelled this wrong, it is really spelled as ....." They will most likely answer you, repeating your misstated Greek in correct phraseology and then ask you to reply.
Modern SLA (Second Language Acquisition) has taught us that errors are part of the learning curve; students level structures, e.g expecting all genitive words in -ου to act identically . In the Audio-Linguistic learning methodology (taught in the 1950's-1970's), any incorrect production was avoided at all costs. The Natural method and most recent SLA studies have shown that errors are a natural production of a student trying to put together a predictable and understandable presentation of language. When teachers over-correct language errors in a new learner, it can cause an affective filter, which means that the student/learner will draw back, become apprehensive, and not want to engage in 2L communication. On Schole, we want to avoid this.
Studies in Second Language Acquisition have shown that early on, the ability to produce content (written or spoken) in the 2L is an ability that comes later, rather than earlier, in the learner's abilities. Children work up from words, to phrases, to sentences. It is rare, that a child is silent and then begins speaking complete sentences (My brother-in-law was one of these examples; He did not speak until four years of age and then spoke in complete sentences. (He has an IQ of about 165). So on Schole, we don't expect learners to produce content (complete sentences), but we try to encourage them to produce answers. Most of this easy stuff can be done in the Chat, where the content is not saved -- after about 2 days, no one will ever see what a person wrote ever again.
For those of us (almost 98%) who have learned by the grammar-translation method (i.e. you have to translate any given Greek NT passage into your native language, before you can understand it), it is extremely difficult to recall or create content. (I was one of those people). But creating content starts with words and phrases, not sentences and clauses and periods and full-blown complicated clauses. If a person feels that he needs to spend a whole another year learning grammar via the grammar-translation method, before he starts communicating on Schole, he/she is short-changing themselves. Such an apprehension is "an affective filter," which is actually an impedance to learning.
It would be my hope that those teachers of Koine for 1st year students would make it a requirement for every student in their class to sign up on Schole and try to talk (in Greek) about who they are, where they are studying, what they did today or yesterday, and what they studied or learned today. It is not going to hurt the student to start to compose the simplest of concepts in Greek. And much of what a person says is in the present tense, or aorist. Most simple conversation (take Plato's dialogues) is simple.
On a note about formal composition: The GreekStudy group (an online community) ran a Sedgwick Composition group several years ago. I led the group. Most NT students do not want to write about Xenophon's Anabasis and Sedgewick is focused on those sort of sentences. What is needed for NT studies is a NT composition book, which is based on NT passages. But in the meantime, if someone wants an online Sedgwick course, we could try another go at it on B-Greek or the GreekStudy group. But I would much rather try to have students read a number of passages from Luke and Hebrews, and then try to write (create content) in Greek. Most Greek composition classes are meant for 3rd-4th year students. Schole has no such limitation. It is meant for beginners and advanced students. It it a community. And it takes a village to teach/learn a language.