Awesome. Thanks for sharing. We used to grow about 12,500 of Flower Carpet Scarlet. Both it and FC Amber, which came out in the US the same year, were decidedly different than the rest, which grew more horizontally – except for Flower Carpet White, which is nasty. FCW is more vertical and blackspots like no tomorrow. Also, the flowers hate rain. Flower Carpet Red is only marginally better. The growth is more appropriate but it blackspots and mildews, lol. FC Scarlet is definitely an improvement. FC Appleblossom is actually my Flower Carpet of choice of the whole series for landscape design. It is healthy, grows properly and adds a nice ethereal touch. Unfortunately for it, commercial sales favor eye bleed colors.
I would always tell the supervisors to only trim Scarlet and Amber slightly. We did not carry white. Someone made sure it disappeared in the same manner that Rhus and Physocarpus ‘Nana’ “disappeared” 
I would also draw diagrams for everything, elsewise there was no proof they had explicit insructions. If there is one thing to know in both wholesale and commercial, it is to be able to easily backup yourself. They are industries of everyone pointing fingers everwhere but inward. So, yeah, I am definitely aware that FC Scarlet is a bit different. The one thing I strictly recall about it is that the tone is harsh, which is not really displayed on HMF. None of the photos really represent it clearly. One can clearly see that it is two overlying tones of a harsh orange and a harsh red-pink. Sometimes it has a faint touch of purple near the eye zone if you care to take the petals apart. Someone should see what it can do when crossed with mauve, lol.
Your info and pics save me a lot of time. Obviously, it is probably best as a pollen parent. FC Amber seems to be of a similar persuasion. I guess they are cursed like Baby Love is. I am curious if FC Scarlet would do well on climbers. For example, Dreaming Spires x FC Scarlet could be nice. DS is already really healthy and it sets seed like mad. FC Scarlet could be useful in giving it more modern scale, as well as perhaps some salmon tone. Climbing minis are nice in theory here, but they fail in practice. It is just too much vertical finite mass, leading to mass blackspot. True climbers with more appropriate scale for modern gardens would be nice. Another use with Flower Carpet Scarlet, assuming that it is tetraploid, is that it seems like it can be bred directly into modern floribundas and shrubs. It does not have as much of the wichurana foliage that Pink has, but the foliage feels like plastic, which is generally helpful. I wish there was a study out (maybe I missed one?) that showed relative foliar disease tolerance vs. foliage cell mass structure, as opposed to strictly resistance via genetics. I have always felt that genetic resistance + a highly defensive cellular structure would be pretty awesome. The one thing regarding the latter, which I have seen, is that even though the mature growth is iron clad, the new growth can be prone. I have seen this with blackspot in my own ‘Rock Creek’, as well as a watermelon pink seedling of it with Cherry Meidiland. Anyways, lol, I think FC Scarlet could be useful in both aspects. It has a definite rigidity to its foliage.
The unfortunate thing with this tribe though is the lack of fragrance. Yellow Brick Road is highly fragrant in Portland. I have no clue why, and my gf verified it since my nose is weird, but it is very snifferific yet it has the typical wichurana brand to it from the Flower Carpet lineage. It smells like Golden Masterpiece x_X. Kordes has some floribundas from the FC series. Theyre nice but they really miss the mark aesthetically. There is something about them that makes them entirely easy to miss while walking by. I am not sure if it is the way the flowers are displayed on the plant, the contrast of the deep green foliage or what, but it is something to be aware of when working with this series. I passed by a display of various cultivars @ Washington Park. I walked by them on several trips before even noticing they existed. They almost had that affect that azaleas do – you only notice they exist when they are in their prime. Maybe the foliage is too nice! Blush Flower Circus on HMF seems to mirror the experience. It is really easy to pass over.
I also wonder how it would behave when mixed with diploid/triploid types, especially if it is itself triploid. The selfs do seem like they are peonin-rich like many diploid reds similar to it, such as Happy, Red Fairy, or Bukavu. A healthy does of pelargonidin mixed with the other reds is usually helpful in making reds more rich and colorfast. It would be cool if it could be passed into diploids via FCS rather than having to deal with the mildew-messed that the orange diploid polyanthas are.
A lot of possibilities and pitfalls to consider. Thanks.
I am glad it is clay thoough. If it was sand, Oregon and Washington would be in the ocean