thanks for the answer
point 1 clear can use only their 4 years old device as bridge mode
It not to has better speed but transfers big files from NAS >< PC with 2.5 or 2 × 2.5G( i have NAS, Switch, and PC all with 2 X 2.5G)
idea is Their device 1G port to RT 2.5G to Switch ( Tenda with 8 × 2.5G) from Switch to NAS 2.5
Rt WAN 2.5 from XT12 main router via cable to Sagecom >> rest are nodes Aimesh and are in different rooms
here is setup picture, even in garden i have over 200Mbit/s which is more than enough
Setup
the Quickline Modem 5530 will not help?