Skin in the Game is about showing that you are willing to accept the risks and costs of standing up to your values. This is a separate thing from "I will only give money to X if they are willing to be subjected to my personal purity test".
I am not saying that donating to me specifically would be a display of SITG. You (and by you I mean "anyone that wants to keep using Lemmy but is worried about potential GDPR violations") could, e.g:
- get a lawyer to work and make a real assessment of the legal liabilities for admins and users in the EU.
- take initiative to pool together resources to find other Rust developers who could work on the Lemmy source code, pay them instead.
- contribute to a competing project to signal to the Lemmy devs that this is important.
- go ahead and tell the Lemmy devs "I am willing to contribute to your work specifically to reach the GDPR-compliance milestone"
The offensive part of your previous post is not that it makes the donation conditional on a milestone, but just you came as someone who is trying to use money as a way to control my behavior. You basically said "I don't like what you did before, so I will only support you for something that I do like if you disown your previous actions". This is completely removed from SITG and reminiscent of a struggle session.
To my understanding, the key part is that you are supposed to disclose any type of information that you are sharing with third-parties through back channels.
If you set a third-party tracking cookie on your site, then yes, the third-party can use the cookie to correlate users from different sites. But if you do what you just did and place a image that displays the IP, how can any third-party access this information? You have my IP and a request log, so what? Is there any way that another Lemmy instance can use this to identify me?
And distribution/collection of public information is not what the GDPR is trying to regulate!