Is bad to use the AMD Radeon HD 6770M al the time in a late 2011 MacBook Pro?

Hi!

I just got a new-used Apple Cinema Display and I'm using it with my late 2011 Macbook Pro 15'. This was one of the affected MacBooks for the glitches and since I was covered by the Apple extended warranty the whole motherboard was changed in 2013 or 2014 (I don't remember).

Either way... I've noticed that when I connect the external display the laptop witch to the AMD Radeon HD 6770M 1024 MB that had problems in the past. The temperature of the computer rises a little bit more often and the fans works a little bit more and usually at constant higher temperature, whether I use the external display alone (in closed-clamshell mode) or in conjunction with the laptop screen.

I'm wondering a couple of things here.

1. Is this setup "safe" for the laptop in the long run? of I'm risking a little big to much in a computer that old to have a failure in the long run for the rise in temperature and usage?
2. Do the new motherboard installed the same problem as the old ones, or are they totally brand new without a known problem? I mean... the previous problem seems that have shown up because the GPU melted the connection with the motherboard after a couple of years of usage. So I would like to know if I'm risking to have the same problem again the (near) future if I continue with this setup.

Thanks for any kind of insight beforehand.

PS/ They changed the motherboard in Finland, and it wasn't under the replacement program Apple set in place in 2015.