I140 Approved. Extension after 6 years

I have my i140 Approved from Company A, After Switching to Company B,

Can I use Company A’s i-140 to extend my H1B visa after 6 years max out?

Yes you can use it to extend

If you are changing employers, your new employer will have to file a new I-140 petition. Your priority date will remain the same on the new I-140 approval with the new employer. But, yes, with an approved I-140 you can exceed the H-1B 6-year max.

What if my new employer don’t want to file new i-140 petition? I can only work till the current Visa period or they can extend my visa with my old i-140?