some sites block their access to VPN users, and even Reddit itself punishes VPN users with rate limits (can’t post for 15 minutes). Some sites like grabify can detect whether the user who clicks on a link is using a VPN.
So how do you hide your IP address and your network traffic while also hiding the fact you’re using a VPN?
You don’t…
This is like asking how do you hide the fact that your hiding?
Websites are able to determine what IPs are used for VPN services because those IPs will have a disproportionately large amount of traffic coming from them
You could spin up your own “VPN” but at that point you lose the advantage of anonymity because your traffic is no longer mixed in with hundreds of other people
What you can do is using residential proxy in combination of VPN. Website mainly detect VPN via your VPN’s public IP, which has the characteristic of datacenter origin.
However residential proxy isn’t cheap, it’s usually priced at X dollars per GB of bandwidth, much higher than your typical VPN’s price.
To mask that you are using a VPN, you should use one with obfuscated servers. Some of the big brands offer that option, albeit they are not always really obfuscated.
Avoid using large VPN providers whose IP ranges are well known, get a dedicated IP VPN or setup your own on a VPS. Still no luck? A chain of a VPN and a residential proxy would do the trick almost certainly.
Sign up VPS and setup your own proxy.
Probably not possible. Most VPNs/proxies are easily detected by sites like IPQualityScore. So if a site owner did want to throttle you based on whether you’re behind a VPN or not, they could do so easily. This is NOT to say that Reddit does this.
I hide that I’m hiding by staying in plain sight. 
those IPs will have a disproportionately large amount of traffic coming from them
Not exactly true. While some website do have ratelimit against IP, most aren’t anymore(or configured very loosely) because the wide deployment of CGNAT.
You could spin up your own “VPN” but at that point you lose the advantage of anonymity because your traffic is no longer mixed in with hundreds of other people.
Could you pay for a VPS with crypto and install a VPN service there to maintain anonymity?
That isn’t true.
no, it is true, and I’ve experienced it myself on my account which is over 2 years old. I went to a coffee shop and wanted some privacy since it’s a public network, but I noticed whenever I posted to a new subreddit I never posted on before, I get ratelimited for a bare minimum of a few minutes. But once I turned my VPN off and did the same thing to a new subreddit, I didn’t get ratelimited.
What makes a residential proxy different from a VPN other than advertising more unique/specific gateway attributes?
The purpose of those servers to get around firewalls, it has nothing to do with hiding the fact that you are using a VPN from the website.
Ah, a forward proxy, this would help somewhat, people would see traffic coming from your VPS vs your house’s router. It wouldn’t be quite as anonymous as using a paid VPN service, but still better than not using any VPN.
Where this really helps is from a security standpoint, most organizations have a forward proxy in front of their network to help keep the corporate machines safer from malware, the proxy would get hit with malware before anything happened to any internal servers, databases, etc… at that point the cyber team can channel traffic through another forward proxy and take down the infected one for analysis
Looks like you discovered that different subreddits can have different rules.
The subreddit you posted on when in a coffee shop or a VPN had a rate limit and the one you posted on afterwards without a VPN didn’t.
Residential proxies are usually hosted by random people (There are offers that pay the people X cents / GB, those companies sell the customers IPs as residential proxies), these connections are residential so the sites can’t just say “Ah, this IP is owned by [insert hosting company here], this must to be a VPN or a proxy connection, I flag it”.
Legitimate Residential proxy are sourced from people who want to lend their Home Internet in exchange for some small cash(or something). Because these IP come from their home like you and me, it makes IP-based VPN detection useless.
However Residential proxy usually provided in SOCKS5/HTTP proxy protocol, which are unencrypted. ISP can still detect/block the website you’re visiting and/or block the protocol all together. A few provider does provide a VPN-like way to access their proxy, but it’s rare.
The other downside is, people can shutdown their computer anytime, when that happen your connection will be interrupted. This isn’t a problem for average web browsing or even streaming as those service would retry and the provider would rotate you to next IP, but if you are gaming, that’s bad news.
This is not correct. Obfuscated servers have an additional layer of encryption that, in theory, hides the traces of VPN protocol info in the data packets.
Surely he would have attempted to reproduce this by actually having the same input (eg. same subreddit), right? … right?
Not really possible without making tons of accounts since the block is for accounts that never posted on that subreddit.