Some key points (credit to reddit user showmeufos):

• They found 700 spherules using their magnetic sled, and thus far have analyzed 57 of the 700 spherules.
• They conducted mass-spectrometry on 47 of the 57 analyzed spherules thus far. Of those 47, 5 spherules reveal "a distinct extra-solar abundance pattern."
• Since IM1’s spherules melted off the surface of the object, the enhanced "Be" abundance might represent a flag of cosmic-ray spallation on IM1’s surface along a extended interstellar journey through the Milky-Way galaxy. This constitutes a fourth indicator of an interstellar origin to IM1, in addition to its high speed, its heavy element composition and its iron isotope ratios.
• The enhanced abundances of heavy elements may explain the high material strength inferred for IM1 based on the high ram-pressure it was able to sustain before disintegrating. The high material strength inferred for IM1 can potentially be tested experimentally by assembling a material mix based on the “BeLaU" composition, with proper compensation for lost volatile elements.
• The "extra-solar" spherules have abundances of the elements Be, La and U, (abbreviated "BeLaU") by up to 3 orders of magnitude more than materials found within the solar-system do.
• "The 'BeLaU' abundance pattern is not found in control regions outside of IM1's path and does not match commonly manufactured alloys or natural meteorites in the solar system."
• This evidence points towards an association of "BeLaU"-type spherules with IM1, supporting its interstellar origin independently of the high velocity and unusual material strength implied from the CNEOS data.
• They suggest that the "BeLaU" abundance pattern could have originated from a highly differentiated magma ocean of a planet with an iron core outside the solar system or from more exotic sources.