The Travel Tripod is indeed compatible with many Arca-compatible plates and L-brackets.
How? The ball head's removable pins allow longer plates and L-brackets to lock in place.
While Arca is the closest thing there is to a standard tripod plate geometry since about 85% of professional tripods use it, we still say "many" and not "all". We've learned over the years that there can be slight geometric variance across brands.
Best way to get it sorted is to head down to your local Peak Design dealer and get hands on with it.