Linkedin sign-in to then ask for contact - too "hard-sell"? And what about freeloaders?

Let's say I built a free website with some useful functionality dedicated to the particular niche I work in, and put some of the most useful content behind a "log in via LinkedIn" button. The aim is to advertise my services and (after a few days) manually make new connections on LI, of course (as I'm failing to productize other stuff and I really need work right now). The fact that they might be asked to connect to me on LI would be stated on the login page, and obviously they would not be forced to accept the connection. Do you think it would come off a bit too hard-sell? But the real question is another...

By law (Europe, GDPR etc etc) I must let users delete their data, which is fine; but how would I deal with freeloaders who could sign up, get the goodies, and then immediately delete their account before I had a chance to connect on LI...?

I thought of two approaches but I don't know if they would freak people out:

A) immediately post-sign-in, trigger a contact request on LI. That would look a bit spooky, imho, and possibly put people off. It would also trigger indiscriminately, whereas I'd like to have some supervision on who I contact (there are people I know I wouldn't want to call, it's a small world).

B) on requested deletion, state to the user that it would be effective in 48h and trigger an email to me, so I get a chance to make the connection anyway. This is less spooky but I personally find this sort of artificial delay pretty annoying when I encounter it (because it often turns out that the deletion will actually never happen).

C) delete the account but store names in a separate database, which I then peruse at my leisure. This imho would really break the law (UK, but i expect anywhere in EU and probably California too, nowadays).

Bonus question - do you think it would be cheeky to add these emails to an -announce list for (extremely rare) mailshots when I release new projects in the same niche...?

Thanks for any feedback you might have on this.