Create a dual-brand design route for a coffee shop

We are an established coffee shop brand, shortly going into a new territory in partnership with another coffee shop local to that territory. We want to build 2 new sites that are dual branded to introduce our brand into their country, then over time we will remove their presence and just have our brand. So, right now we want both brand logos to sit together comfortably and need a strategic brand design path illustrating various routes. From best route, areas to be worked up across all branded areas such as store fascia (flat and projection signage) and core collateral (such as take away cups, crockery, uniform).

Each logo stays true, as in we dont want to create a new name by almagamating part of each logo. Probably a 65/35; 70/30 and 50/50 split in terms of hierarchy, with our brand being the dominant.

Colourways would be across our brand colours - so 2 routes for background (black and then blue), and this will then affect the type colour. Font also stays true for our logo - this goes untouched, its about finding best way for their logo to sit with ours, but being sensitive to their brand and not confusing their existing customer base, well as much as we can avoid that anyway!