I have extensively researched…
I wouldn't use the word "extensive" until I had the answer to the question you pose already in hand. Instead, you've got a question so vaguely posed it makes me doubt you've done more than a preliminary survey of the available options. You don't even name the product range you're most closely looking at. There are 180 products in MikroTik's line that can run RouterOS, thus could in some sense be called a "RouterBoard." It extends from tiny devices like the CRS106 to monsters like the CCR2216 that are rivaled only by hand-built servers in the same weight class as your ESXi hosts, running either CHR or the bare-metal x86 version of RouterOS.
Your title question can't be answered in yes/no fashion even once we know what in this wide range of options are you looking at. We'll need to know what workloads you expect the product to handle, for a start. We can make assumptions, but I can tell enough from your question that you know where those lead.
I intend to connect all the hosts, including the uplink switch (if it has 10gb), via the RouterBoard.
That sounds backwards.
If you're using a RouterOS device as a router, it would be best positioned upstream of the switch connecting the hosts, not downstream from an "uplink switch," whatever that is.
If instead you're looking at RouterOS merely to get around the HTTPS issue you brought up in your only other thread here so far, then you're asking it to be a glorified switch, not a router, which then makes me wonder why you have an "uplink switch" in addition to it?
Furthermore, the fact that you've only got three hosts plus an uplink makes me question why you're talking about a separate switch in the first place. Even the itty bitty CRS106 has six ports. What is this other switch buying you? It matters because it will get to the workload question.