Nothing new here 
( been doing this stuff for a while )
The convolver has a high pass filter inside to prevent dc off set .( that’s one of the reasons it sounds different to other I.R. reverbs )
I did a lot of testing in the past .
here the’s thread , and yeah dev’s don’t give a damn ( or don’t have enough time maybe
https://forum.renoise.com/t/convolver-applies-dc-offset-filtering-to-impulse/44886