OK, I'll bite. There's probably 2 big areas to look at. There's structure, strength kind of things and there's geometry stuff.
Trailing arms are also a big subject and I'm not sure off the top of my head the names or categories of them all. We are not going to talk about the kind used in the front suspension of a VW Beetle or the semi trailing arms in a BMW 2002 or early Datsun Z car ( showing my age here
).
I have not spent much time looking at or thinking about transverse midship cars. They make sense these days because of the large amount of donor hardware available. On the other hand when they go sideways maybe that is mother nature trying to straighten them out? I don't know.
For geometry, at least to start, I think you can use tools like Vsusp or other and consider them like double wishbone designs. The lateral links control the camber, toe and roll centers, just like wishbones. Depending on the design there may be toe changes with bump and droop as the trailing arms move the uprights fore and aft, due to their length.
A big issue here is finding places to mount the suspension to the car. With the rear suspension there are also the halfshafts to consider which may make the frame more difficult or require offset of the coilover/pushrod mounting to the upright. This later issue can be considerable, I worked on a car where issues were traced to flex of the control arm caused by this offset of the coilover mount. FEA showed the arm was warping by a couple of inches.
I chose trailing arms with a reverse lower wishbone for Car9 and I have recommended this and similar style setups a couple of times. This was useful in this case because it only required two inboard mounting points on each side, ignoring the coilover anyway. The bulkhead behind the driver easily supplies these, you could cut off all the rear tubing behind the driver and the car would work fine. This bulkhead can be made very strong for sideways loads. The trailing arms mount to the sides of the cockpit somewhere and this also can be very strong for fore and aft loads.
The trailing arms take all the torque from the brakes and coilover, the IRS diff takes all the torque loads from the engine. To me this seems easier to figure than the twisting loads you deal with in pure wishbone style setups. Not that that can't be done, but many people just build something that looks right and that can lead to trouble.
Next step is to look at your car and maybe think out load with 2x2 wood and look at how you're going to mount your motor and look for places to mount control arms...