Buying expiring domain for PBN... how to avoid this?

Hello guys.
I'm trying to backorder expiring domain with good backlinks number.
So far I win a domain with 80 good backlinks.
But now my question is: should I avoid to use the same service for this domain?
For example, if I won the domain using NameJET... should now I use different service like GoDaddy for backorder?
Should I avoid NameJET?
If I should avoid to use the same backordering service... what should I do when I get a domain from all the backordering service? I mean, I know just 4 backordering service... PBN of 4 sites it's pretty weak, I think...

You don't have to change registrar. I have like 5-6 max on each registrar account

No an issue if you use the same registrar for a few domains.

NameJET is huge, like most US registrars. Having 10-30 sites on there would't be an issue at all since so many sites are using them. Also don't worry about creating a new account for every domain you register, that's a spooky myth. Google won't be able to see it, the registrar gets paid, just make sure you use unique WHOIS and anonymous WHOIS. Also don't use Gmail as your email because registrars tend to send all sorts of emails with your domains in them.

Just get privacy on all your domains if you have a small network.