I'll wait to buy it. But I certainly won't order an ABUS FCA3000 until I have clarification, even though I find just such a product useful.

In my opinion, the BSI warning generally applies to any wireless window operator such as ABUS FCA3000, FSA3550.

At least that is how I interpret the warnings on the ABUS page (see below).

The HomeTec Pro 3100 generation is not affected by this warning.
Unfortunately, the HOMETEC PRO FSA3550 RADIO WINDOW DRIVE is also only available with this warning.

The only option is to write to ABUS. I will follow up on this. Or another user has already done so ;-)

can be found at ABUS:
HOMETEC PRO FCA3000 as well as HomeTec Pro 3100s.
User-friendly and secure: With the wireless window drive, you can lock your patio door conveniently at the touch of a button. An alarm function puts burglars to flight.

Note: the BSI has published a warning regarding a technical vulnerability for the CFA3000 radio door lock. The radio window operator uses the same technology.

This only applies, if at all (there was no warning for the FCA3000), to the old models. The question would therefore be whether the products sold by Digitec are still the model before the revision, i.e. manufactured before March 2021. In contrast to the door opener (CFA3000), it is not possible to see from the outside whether this product was installed on the patio door. The chance of something happening here is probably negligible. Otherwise, this is a very recommendable and practical tool!