As such, you can buy "Velcro [BVBA] velcro", or you can call 3M's hook-and-loop fasteners "3M velcro". 3M, naturally, avoids using the term "velcro" in its packaging and marketing, and would never use "Velcro", because even though they could, because the term is genericized, it would still be free advertising for a competitor.
Capitalization has no bearing on word marks (in the US, at least. I can't speak for other countries). "Velcro", "VELCRO", "velcro" are all the same thing as far as the trademark office is concerned. And yes, there are still active trademarks for the word "VELCRO", but it has still been unquestionably genericized.
In the UK I can go in to shops the length of the country and ask for velcro and get "hook and eye" or "fabric fastener", is a completely generic term now, just no one wants to fight it in court.
* UK trademark record, https://trademarks.ipo.gov.uk/ipo-tmcase/page/Results/4/EU00...
As an example of all-caps trademark, LEGO bricks. Like velcro, LEGO is a portmanteau. Velcro is velour-crochet, and LEGO is leg-godt ("play good"). And like velcro before it, LEGO is now fighting genericization.
If they lose the struggle, kids will play with legos instead of LEGO bricks. They might be legos made by Lego then, but LEGO would be the trademark. It might not be relevant to the word mark, but the image mark is stylized in all caps.
This is nitpicky, but I am sharing some of my experience from writing software that produces brand reports for trademark lawyers. The USPTO might not be case-sensitive, but some of the lawyers are very case-oversensitive, so our software had to take that into account. I still have trouble using a trademark as a noun or verb.
I think the original poster meant "genericized" instead of "lapsed". But Velcro is clearly already genericized, as you note.