Could you check this over

I suppose so, although I don't know what abstract t-stems are, exactly.

Search for "t-stem" it on this page. They would also give forms such as:

• *-tuHts: Latin -tus, Celtic *-tūts, Gothic -𐌳𐌿𐌸𐍃 (-duþs).
• *-teh₂ts: Latin -tās, Greek -της (-tēs) and Sanskrit -ताति (-tāti).