Ethernet Network vs Router Upgrade
Apologies for long post but hoping to include all relevant info to get best advice.
Obviously, ethernet cable is better where possible but due to needing permission for permanent changes, I am seeking advice on options/solutions.
Nbn HFC 500/50 plan. Achieve 250-300Mbps on PC with 6e wifi card from an Telstra Smart Gen 2 modem router (wifi5) over wifi 5Ghz. 2.4Ghz on old laptop is 80-100Mbps for comparison in same area. Ethernet cables will run full 1000Mbps download (about 980 via 6a cable 30m).
Double brick house (internal mostly single brick but one double brick wall that may also impede signal) with neighbours all on similar tech and bands. Changing to less congested channel does not see any real differences.
Placement of NBN modem can't be moved (2 rooms away including brick walls) from living space (helps for tv/mobile devices anyway) and can get 400Mbps on ipad. All devices would be wifi5/6/6e compatible.
So asking advice on new router options where wifi 7 is wasted so leaning towards wifi6 router and wondering if triband would be helpful (seems only good for same room device) or just stronger 5ghz performance. I dont want Mesh set up as the second router would have to be next to pc anyway. Flint 2 seems a decent pick but open to other suggestions.
Alternatively, to get permission for some cabling to be installed from owner.
How would this work? 6-8 devices across different rooms cabled to a switch (in roof space??) and then just 1 cable from wall port to modem/router or would I need to get 8 port wall plate running all cables to switch (then patch cable to router) or all lines from wall direct in to router (need router with enough ports). Unfortunately there is no attached garage or similar to hide the ugliness away so trying to present an option that won't look too much worse than standard electrical wall plate.
Dont need full speed for anything other than large download files on occasion so existing temp cable along floor works but if a better router will beam wifi at same speed that may be worthwhile (my expense) or to explain future benefit of cabling (owner expense) I need to visualise and explain how it would look different to current set up.
So for the TLDR:
Will an upgraded router improve wifi speeds to 500 or closer to 1000Mbps if there are internal brick walls or am I getting max speed already?
How do I run ethernet cables between various rooms to single point at Modem/router without it looking like a dog's breakfast?
Thanks in advance for all help and if there is better sub for this with Australian specific advice, let me know.