Wifi ethernet jack recommendation

I have used the tp link AX 3000 range expander, I see them for $ 99 on line.Works great, runs Wi-Fi with an out Ethernet jack. Great reception, it is in my upstairs loft and my router is in the basement. 

I placed my entry fiber AT&T modem in pass-thru mode (to avoid double IP address) and use 2 piece TP-Link DECCO XE75 Mesh routers (with Ethernet outputs).  Selecting 6E type router (tri-band) was important to me because there is a lot of traffic nearby on 2.4 & 5GHz.  First unit is plugged directly into AT&T modem and communicates with the second on 6GHz.  There is no traffic on this band here yet and so far I have not experienced a single drop.  My computer modem works on 6GHz and everything else works on 5GHz (including Airport Express).  I eliminated 2.4GHz band since I don’t need, but others use it (to be a good neighbor).  Modems like one from AT&T or TP-Link DECCO allow simultaneous transmission on 2.4GHz and 5GHz claiming better performance, but I found that it often selects 2.4GHz where signal is stronger (penetrates walls better) with only three independent channels (each channel 3.5 of 12 channels wide) - a lot of interference.

6GHz will be much less crowded for a while, and turning off 2.4 (with only 3 non-overlapping channels) is a good idea.   6GHz and AX-E has MultiuserMIMO which will stay 'on' vs.running AX on 5GHz (non 'e')

remember that 6GHz will go through fewer solids than 5 or 2.4, so although it can carry more bandwidth per unit of time (higher freq), it attenuates more through walls so has less reach inside buildings, so don't just think "my 2.4 and 5GHz gear reaches from basement to MBR so my new 6GHz kit will too!"

lastly, based on your total throughput needs, select a narrower channel width, your choices are: 20MHz, 40, 80, 160... "why not the widest/fastest?"

well, when running 20Mhz allows for 59 channels and throughput of nearly 250Mbps (1/4 gigabit).  And at 80MHz, 14 channels...  so work with your neighbors to consider not using 160 widths (and only 7 channels) all will be better off using non conflicting channels.

bonus of 6GHz: WPA3 is required, nice since WPA2 has been cracked.

All the opinions are why I recommend using an analyzer first.  Really depends on your home's layout and where you live.  I don't have that many neighbors but for some reason all three of their routers like to sit on the first channel in each band.

Thanks for all the advice, I am still pondering my plan of action. Just got power wiring in yesterday. My 1929 is built like a tank, running new wires can be a challenge, and it was. 
 

I have run an analyzer in the past even though my neighbors are not too close, and did optimize based on the info. Probably worth doing again.