Your photos are breathtakingly beautiful and I would agree that they are enhanced and certainly not "faked". Ansel Adams (who is still the greatest landscape photographer in my book) did much the same as you with filters and supremely skilfull printing that turned his work into fine art. His black skies were in no way natural, but they provided a wonderful contrast to his Yosemite mountains etc
I am still wedded to film and nothing can beat velvia trannies. I have scrapped all filters but a polariser and an 81b warm up which I use instead of the more normal skylight. Personally, I detest coloured filters of the graduated tobacco type and similar OTT effects that digital photographers use - all those lurid sunsets and purple dawns! When does enhancement become fakery? We each will have our own views on that. Keep delighting us with your pictures Cian - they are simply superb. If I may be permitted a word of advice - that would be to change your style from time to time - its refreshing and liberating. Try moving away occasionally from the super saturated colours and try some soft pastel rainscapes.
Thorgrim