I don’t think it’s valid to use “only” with “e.g”. “e.g” means it’s an example, which implies the existence of other cases that satisfy the criteria. “Only” implies some uniqueness of the subject.
“It’s legal to drive only if e.g. you have a driver’s license.”
It’s not a great way to say things but it is meaningful. The meaning is “only if [unspecified list of things], and [x] is an example of an item in that list”.
> However, the “safe” is only valid if e.g. the used supply lines from the power supply with “native” 12VHPWR connector have a good quality and 16AWG lines or at least the used 12VHPWR to 4x 6+2 pin adapter also offers what it promises.
Here’s my interpretation:
> However, the term “safe” is only valid if certain things are true, e.g., the used supply lines from the power supply with “native” 12VHPWR connector are of good quality…
“It’s legal to drive only if e.g. you have a driver’s license.”
It’s not a great way to say things but it is meaningful. The meaning is “only if [unspecified list of things], and [x] is an example of an item in that list”.
> However, the “safe” is only valid if e.g. the used supply lines from the power supply with “native” 12VHPWR connector have a good quality and 16AWG lines or at least the used 12VHPWR to 4x 6+2 pin adapter also offers what it promises.
Here’s my interpretation:
> However, the term “safe” is only valid if certain things are true, e.g., the used supply lines from the power supply with “native” 12VHPWR connector are of good quality…
I can’t interpret the rest of the sentence.