As an investor, i cannot participate in IEO conducted by small and new exchanges. The main reason why IEOs are preferred to ICOs is because they are more prone to scam than ICOs, and this is because the exchange validates its legality with their reputation. Imagine Binance or any top exchange conducting a scam project, it will jeopardize their integrity, and these exchanges do not want their integrity in question, so they only offer legit and promising projects IEO. New exchanges do not have the reputation to validate a project, they are just after the profit, SO they might promote a scam project either intentionally or unintentionally.
Very well said OP, take for example on LAToken since they are well-know exchange these days but still they launched an IEO scam projects that led their user to not trust the exchange so how come if it's a new exchange launching an IEO. it is always recommended to do your own due dilligence before investing on any project nowadays.