https://reportage.transcontinental.cc/?cat=15
This reminds me of a conversation I had with Rimas after his first TCR. I asked how did he work out a route. He said he didn't. He just plotted an A to B on Bike Hike... The day before..
"Rimas Grigenas won the Continental tyres prize for longest route, taking the wide lines through France and Switzerland towards CP2 and venturing a good way East into Hungary before making a right hand turn through Romania en-route to the finish. The Lithuanian admitted . . . he was at the mercy of his routing software."
I wouldn't rely on routing software on a 3000+km ride and those that do are rare.
Why would such software produce a better route than a well planned (by a competent human) one?
Otherwise use
https://cycle.travel/map
I'd go with whatever it comes up with as your basic route and keep the tinkering to a minimum
How about: 'see what it comes up with and adapt that, and check every mile of the route online before riding'?
Keep it simple, be aware that you will never be able to plot the "perfect route"
Would you care to expand on what, in the context of a 3000km cycle, you mean by 'keep it simple'?
A starter in the TCR is aiming to finish and a good, well thought and prepared route, with 'costed options' is one element of a successful campaign. Start without one and I suggest that will reduce the chances of "just enjoy[ing] it".
I've inserted the start, finish and controls into RidewithGPS and the route it offers is:
https://ridewithgps.com/routes/29284468?beta=false
Caveat randonneur/racer.
There are at least half a dozen draft TCR No7 routes on RwGPS ('Find' tab and set start to Burgas, Bulgaria and distance to 'over 500k' (ie the max)).