Andre's documented accounts of breeding Heckels is the most credible of any I have come across in many years. Having seen most of his youtube videos I am completely convinced of his successful accomplishments.
I have a feeling that F1 Heckels are probably going to be nearly as difficult to breed as wild fish but not quite as difficult. Still likely to prove that very few who manage to obtain any of Andre's F1's will be successful but only because I think F1 is too soon to gain any domesticated traits. They should be parasite free and I think that is one thing which will make it easier to get the F1 females into breeding condition.
I think we are still many years away from establishing some purebred, tank raised aquarium strains of Heckels but at least we have seen some progress thanks to Andre's success and adequate documentation.
It is not too difficult to maintain a pH of 4.0 in nearly pure RO water. It is hard to reach 4.0 without using Muriatic acid and I really do not think there is any need to try to keep the pH below 4.0.
By most standards if the pH is as low as 4.0 that would be difficult to lower any further without using more Muriatic acid. Once the pH is at 4.0 it won't crash to a lower pH by any natural means I am aware of.
I have found the statements that Heckels are not bred commercially because there is no market for them an incredulous assertion.
The comments in posts about Heckels I have seen on the Singapore based aquarium forum, www.aquaticquotient.com indicates a considerable interest in keeping and breeding Heckel Discus.
They are always very excited about whenever some wild caught Heckels become available in the area and they seem to want to breed or buy tank raised Heckels as badly as North American wild type Discus lovers.
I started a topic asking about the availability of Tan's TR Altum Angels and found that they were not being made available but there are many hobbyists already thrilled to be able to get any wild caught Altum Angelfish which manage to make it to Singapore. It parallels in many ways the Heckel's popularity in SE Asia.
So to say there is no market for TR Heckels sounds like a hollow claim to me. It sounds more like a flimsy excuse to cover the lack of success the SE Asian breeders have had with Heckel breeding that those in the rest of the world experience.
Vlam breeding Heckels doesn't ring true to me. Vlam has been one of my Pleco customers and he knows how interested I am in breeding all species of wild Discus. We have traded e-mails having to do with breeding plecos but he has never once mentioned that he has bred or is breeding Heckel Discus to me in any of our conversations.
In fact, that he is breeding any wild Discus has never come up in our e-mail conversations.