Actually, the TMO map is visible in a couple of places inside the FotRSU modded game, though it is boat-dependent as to where you'll find it. There is another version attached to the Shortwave Radio screen. Now, if you install vickers03 Interiors on top of the FotRSU mod, then you will limit the availability of the map (see image below). If you use the AddOnModzPak for FotRSU, that places an "Extra_Info \Research \Various folder under the Support folder, and that is where the image is now (see image below).
As KM suggests above, you do NOT have to follow orders in the game, and can go anywhere you desire to sink enemy shipping. Most Objectives in the game are worth 300 Renown points only, while small merchants are worth that, larger merchants more, and warship quite a bit more. The only thing NOT following orders does is basically disables the Status Update from giving you another Objective. Sink ships.
However, if you do want to attempt to follow orders, as any good submarine commander would, then you want to find your hidie holes first. Those are where you will go deep when necessary. Some areas are just not good for that, such as the Java Sea (the worst possible overall area to attempt to patrol). This is where the mission orders come into play. There are "key" phrases that might let you know that you can leave your patrol area and come back in later, and the time will continue from the re-entry time. Most patrols though, are what is known as "continuous time", where you have to stay inside the area for the duration. Formosa Straits though, usually has several spots where you can get deep enough to avoid. If one is inside your patrol area, all the better. Patrol perpendicular to expected traffic lanes (basically the ships are northeast-southwest, so you'll do northwest-southeast lines). It might be that you stay in your hidie hole through the daylight hours, then surface and hunt at night, returning to your hidie hole before daybreak. If you do not have a hidie hole, but insist on completing the Objective, then it is just a matter of remaining hidden, out of the way of traffic while submerged. You would stay out of the traffic lanes, submerge as deep as you can, and only come up for short periods to refresh the air and charge the batteries, mostly at night. Do not attempt to sit on the ocean floor - the sub will incur heavy damage, probably dooming you and your crew to the spinning "End-game" screen. Once your Objective is fulfilled, get someplace safer to hunt...
Now, another thing to remember, especially if using RSRDC, but mildly so in FotRSU also, is that the traffic patterns change slightly as the war progresses, with new routes being used, usually closer to shorelines, especially later in the war, from late 1944 to the end of the war, especially along the Chinese / Korean coasts, but also Japan and Java etc...
