Are you referring to the Sailrite Ultrafeeds? LSZ1, LS1 or one of their industrial machines?
The LS series has a lower presser-foot lift and you’ll have trouble with thicker foams there. Its possible, but requires significant compression of foam to fit it all under there.
I used an LSZ1 for two years of building packs and gear before buying a Juki DU1181N. I lent out the LZ1 to a friend and use it occasionally for bartacks as I save my pennies for a programmable bartack machine.
If I could do it all over again, Id skip the sailrite and get a proper industrial first. The higher foot lift (with knee lift!) makes doing shoulder straps and thick webbing on packs so much easier. The lack of a zigzag can be overcome in most places with appropriate design.
Unless you absolutely need the zigzag, get a walking foot industrial like the Juki  DU1181N . The price difference is minimal for the utility the larger machine provides.
https://www.sewingmachinesplus.com/juki-du-1181.php The Juki may actually be cheaper depending on your table setup on the sailrite. Absolutley worth it.
Hope that helps!
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