Question About E39 Remapping

Hi guys,

I have an e39 530d 193hp with 212000km, car is in very good condition and I would realy want it to be remapped for some extra hp. I emailed a local tuner here, and he said he wouldn’t recommend it because it has so many miles on it, and that this engine is not reliable to start with even without a tuning/remap! I had an E46 330d with 184hp and an E38 730d with 163hp, both were also remapped, the 730d even had 245000km when I did that and never had problems with it, so I really don’t know what to do?  The tuner I emailed is a very well known one, so they know what they are doing, but I called other known and skilled tuners and they are willing to do it; so I really don’t know what to do here.  Are these engines really that unreliable? Should I just go ahead and remap it or leave it like it is?

Hope this time I’ve posted this in the right place.

Thanks in advance guys and hope you can help me, cheers.