Help, need a 4-5 port switch with at least 2x10G ports

Hi,

I moved into a new flat a few months ago and the ONT was installed in another flatmates bedroom. UFF said it's going to cost 2K to move it to where we've set up our office.

Currently I have a cable running out the bedroom window to get to the office where the router and everything else is.

I am wanting to upgrade to an XGSONT and have a few secondary connections on it so I can do some testing for work from home (better than going into the office at midnight...)

I would rather not annoy the flatmates and have multiple cables going out the window so was thinking about getting a pair of VLAN capable (bonus points if it supports double tagging) switches, one for the office and one for the bedroom.

I'm thinking it'll go something like this https://ibb.co/VMMgG85

Problem is the ONT expects VLAN tagged packets (I can change that but I'd rather not), so I'm wanting the switch to push a second tag on top, it'll get sent through the trunk port and the other switch will pop that outer tag. This is so for the devices at either end it'll look like they're directly connected.

The MikroTik Switch CRS305-1G-4S+IN (https://www.gowifi.co.nz/switches/crs305-1g-4s-in.html) looks promising, I'm familiar with MikroTik and know they're fairly customisable.

Just wondering if anyone has used one before and know it'll do what I want? I.e does the switching chipset/ASIC support vlan tags or even double tagging (having to go through the CPU for tagging will kill the throughput), does SwOS support this kind of tagging?.

Or is there something else you guys suggest? Will need at least 2 10G ports, I'm not fussed it it's RJ45 or SFP+

TIA

Double bonus points if you guys know of a cheap UPS that'll run an ONT and Switch for a couple hours