I think you need to recognize that the DAZ store and Rendo are operated differently. I don't know all the details, but it is clear that DAZ itself provides the first line of support for the products sold in its store. At Rendo, if you find a problem with a product or have a question, you have to contact the PA directly. Rendo makes it easy to contact the PA. DAZ makes it difficult, because they are the first line of support. DAZ wants you to contact DAZ support.

My experience with contacting Rendo PAs has been very good. On two different occasions I found problems in the DS version of recently released products. Both PAs responded quickly and got fixes out. These were both products that supported DS.

Some of the PAs at DAZ frequent the forums, and are fairly easy to contact.  Sometimes DAZ support is pretty good, sometimes they get backlogged and it can be a long time before they get back to you.

Because DAZ does first line support, they also have a QA process for products in their store.  I'm not sure Rendo has any QA process for the products. They may leave that to the PAs. One of the problems I found in the DS Mats for a product should have been caught by any QA, so I doubt there is any QA from Rendo atleast for the DS versions.

Rendo and DAZ both rely on PAs for most/all product development. At this point, DAZ probably will not accept new Poser only products for their store. They can get away with that because they are the biggest store, and realistically a lot of their customers are using DS.

Rendo is probably not in a position to insist products support both Poser and DS. Rendo wants products that sell well, and since the DAZ store has very few new V4/M4 products, customers that want new V4/M4 products generally come to Rendo. Realistically, many DS users mainly use Genesis now, not V4/M4. That means most of the customers for the new V4/M4 products are Poser users. I cannot recall seeing a Poser only Genesis product in the Rendo store or anyplace else.

The biggest obstacle to most products at Rendo supporting DS is the PAs don't know how to use DS. They are busy making new products and don't really have time to learn how to use DS. Perhaps they don't think the extra sales would be worth the effort. Perhaps they are just reluctant to learn something new.

We will have to see what happens with Dawn. I get the sense Poser users are much more interested in Dawn.  I was one of the people that helped crash the HiveWire servers the day Dawn was released. (The server did actually crash when I hit the placed order button. I never got the confirmation page, but the order had gone through when the servers came back up.)  I bought most of the early Dawn characters/clothes that supported DS.  At this point I've decided to wait and see, before buying more. Dawn needs a more complete morph set, like morphs++. HiveWire is working on this. I'm concerned that a lot of the conforming clothes for Dawn being created now will not support those morphs when they are released.

My experience with Dawn in DS is clothes did not work quite as well on Dawn as I was use to using Genesis 1/2. I had more problems with poke through/not fitting on morphed Dawn characters than I would have expected. I think a lot of that is probably inexperienced PAs and lack of a good QA process.  It was clothes from PAs I was not familar with that had most of the problems.

I find it very encouraging that a few PAs (outoftouch, MEC4D) are now starting to make the same clothes for Dawn and G2F. If this is not too much extra work, then this might be a good way for PAs to sell to both Poser and DS users.