Hello,
A feature which is supported by Atheros Chipsets (DD-WRT has it for years) is the ability of a wireless device to simultaneously act as a client AND an AP, without the need for WDS. My old TP-Link router could have two wireless interfaces, one being the client to an AP and the other acting as AP, even with different SSIDs and security settings between the two.
It would be extremely convenient and nice if we could see the same functionality added to RouterOS.