Blue Curve is one of the fastest WiFi you can get. I can't remember if chrome cast has auto switching of frequency(some wireless phones do it). Sometimes building materials cause an issue but the most common is if you live in an apartment or condo the people above you might affect your reception as they could have their own system. Blue Curve uses burst if I remember right and that improves but not as much as burst through rj45 line. Blue Curve is useful when your in your garage, basement, or just outside your home for reception and security on the wifi. But the speeds still have limits.
If you are inside a home you want it wired with cat6 or cat 8(depending on your needs it should only be cat 6 for ethernet outlet plates). It will do much better and allow TV and computers to reach maximum speeds. Provided for the TV if linked to a computer your using a 4k or 6K hdmi cable. For inside as well if you use a splitter of any sort like a router which could use an rj45 cable in, and others out(or wifi) make sure the in/out rj45 are both cat6. Usually speeds noted for wifi/ethernet routers are saying the highest speed for the wired part and a second high speed which is lower for the wifi part. A lawsuit did come up years ago with a business and private individual over speeds and claims on speed for wifi and wired. Some places later were required to state proper cable type(HDMI 4K/6K and Cat 6) as well as clarify WiFi vs Wired speeds from the unit(modem/router aka advanced modem). Some people sued as well because they wrongly wired their house in cat 5(with wall plates) when it wouldn't meet their needs and only met old modem usage needs.(back then a 30K modem was fast)
Burst Bandwidth
Wireless Network Speed Tweaks
There is a specialty tech used for super computers that does get higher speeds but generally it's not out for public use. Wifi no matter the Max Mbps it can get is still split among users of the WiFi at the time. As the one article points out if someone else is on the wifi the newer devices connecting suffer a slower speed. Also though speeds they say can get up to 400Mbsp that is not sustained constantly as if fluxes and also since your likely to have more than one user. At first since it's so fast you wouldn't realize but as more go on you do. This includes things like chrome cast which you might not think too much on as TV. But TV can use 1G/h in streaming and can use a lot of bandwidth if using hdmi 4K or 6K at 1080p.
How to change a chrome cast wifi network
How to Troubleshoot Common Google Chromecast Issues
Chromecast Tips and Tricks
If you connect it to a ethernet adapter make sure the cable to the ethernet adapter is a cat 6. I can't remember if cat8 will also work but cat 6 should also be fine. You will need to look it up or borrow a cable to see if it makes much difference for you.
Most peoples blue curve and 300/600 problems probably are just wrong ethernet cable. Regular cat 5 has a clear connector and does 1/2 the speed a cat 6 does. Soon they will be hard to find and you will only get cat 6, 7, or 8 and same with the regular hdmi vs the 4k/6k. Also read the info carefully on max wifi speeds and network load. The more wifi active the harder it gets. 1-2 connections don't notice much unless one is heavy tv and the other tries to game. Then you will notice it perhaps. Otherwise light to medium usage on wifi people aren't likely to realize a speed issue unless there is poor signal passage in a home and sometimes this is done for health reasons.
Some rooms might have more shielding for other electronics as well. This gave rise to some alarmism on radio signals and cancer. Most times there isn't a huge problem. But high constant bathing in it probably isn't good ie off when not in use or don't leave it on while you sleep. Wired is more healthy as wires are shielded sometimes. If your using over a 6-10ft cable get a shielded cable of whatever your using or you get noise/interference and it's also not healthy(like living near high power lines aren't healthy). Some newer apartment buildings and homes must meet a newer wiring standard as a result and wall materials. This prevents leaking wifi and reduces line based radiation.
