It'll be fine. VW TDi engines are durable in the extreme. Usual rules apply as for ANY car, mapped or standard.
1. Cold start & let it idle for a minute or so before driving off;
2. Don't short change on servicing, oil change every 10,000 miles is a good thing. Use good quality synthetics that meets your car makers specs. I have a liking for Fuchs Titan GT1 Pro C3. This will work very well indeed in your Seat, meeting VW 507.00;
3. Don't switch off when the engine has been runing hard. A couple of minutes cool down at idle will preserve things very well.;
4. Don't under-drive and lug it at super low revs. This is very tempting with a remapped diesel but it beats the life out of everything: DMF will suffer, engine oil pump is not giving full pressure at 1200rpm so lubrication will not be optimal etc etc;
5. Get it hot and drive it purposefully. Visit the red line several times a week. The red line simply indicates the upper end of the usable power range of the engine, not accelerated engine wear. Drop into 4th at 70-80 mph for a few miles a few times a week, get it breathing. or Third at 70 is going to sit you around 4000-4500 I would imagine - that's good too.
All common sense really but I see so many people lugging 4 cylinder diesels. It's pointless, achieves nothing in terms of economy and detroys engines and transmissions.