They are a pain, but a strong connector!
Where did you buy the 8020 from George?
Zoro
Better order fast due to the tariffs. They have good prices, but I got the best deal from them buying them off eBay.
I ordered 2 145” beams from them off eBay and, I think a 72” beam from them directly along with other parts. You can (or could) get good prices off Walmart (believe it or not) or quality equivalents from tnutz.
Hoonly can provide you these T-slot aluminium profiles and accessories. more details please email us: hello@hoonly.com