Venereans in orbit are short on deuterium and on fissile minerals. A fusion engine demands isotopes, energy, and expertise - meaning, money. Upper orbits at least can catch pure-protonic hydrogen from the ion wind, and oxygen too if lower orbits are generous. So Venerean orbital rockets will trend chemical: both in-system and - tetherassisted? - in heading elsewhere. This hints that outgoing from this planet will trend Hohmann. Let's look at how Venereans get to Mars.
Venus, being a (very) inner planet, gets over twice as many Hohmann windows to Mars (0.9142 yr) than Earth does (2.1354!). In that CuriousMetaphor map we don't get a direct Venus-Mars route. We do get Venus-Earth (280) then Earth-Mars (390) at 670 m/s total. Thence 1660 m/s to Deimos before our actual landing on Teh Red Planet, if that's our aim.
Remember, we don't add these together in our vector calculus. We must further grant that both are tilted relative to Venus and more elliptic; and that Mars is tilted opposite from Earth's relative tilt and that Mars is even more elliptic. I expect a straight route from SVL2 to SML1 to cost somewhere between 500 and 670 m/s, porkchop plot willing.Trip time is marked 0.5954 years.
However Venereans do, sometimes, get an off-season option. If they take a Venus-Earth passage, which is at 280 m/s as I am assured, they can use Earth's gravity to assist them to Mars. They "tap the brakes", hurtle down Earth's well for the Oberth Effect, and change their orbit to a Hohmann with Mars. That 390 m/s is no longer in effect; it's replaced by whatever it took to tap the brakes near Earth. That is a good deal less.
The journey does take almost twice as long to the tune of 0.3999 + 0.7087 = 1.1086 years. Since the cargo is bypassing Earth, the corporation handling this traffic may retire the Venereans to replace them with Martians. The crew leave and join by shuttle as usual, taking whatever breakable valuables they need. This spares the humans and other fragiles from the G-LOC in Oberth. The lighter freight is to be controlled by robot and/or remotely.
I note here the radiation hazard especially earlier. So this freight, even relieved of crew and some shuttles, will be heavier than Earth likes, blasting through its LEO. "A shot of hot Pb in the face", I can imagine. Some may recall the anti-Cassini agitations in the 1990s. Earth might demand that some of the shielding be shed into its orbit, also, before the freighters take that Oberth dive.
As to when this additional cheap-o window opens, I expect that we'd line up Venus-Earth arrival (right hand column) with Earth-Mars departure (left). Starting at the end of this century, I spot a pattern of arrive / depart intervals, ever narrowing: 2097.3961 / 2097.3418, 2103.7907 / 2103.7480, 2110.1854 / 2110.1541. Later they start drifting apart again: 2161.3424 / 2161.4034, 2167.7371 / 2167.8095, 2174.1317 / 2174.2157. Intervals are 6.3946 years; four V/E synods apart.
As far as the reverse goes, citizens of Earth (or of Luna) might envy that these routes are cheaper even than their own direct Hohmann to Mars. Such might consider Venus or even E-V-E to assist their own Martian trips (the Cassini route...). Again, these trips take longer and hotter, leading to those "Fry By" jokes. With E-V-E Earthers worry about that lead gunshot. Also if one gets too far down such a well the atmosphere starts dragging, definitely a concern at Venus. And Earth and Luna both enjoy access to all manner of energy resources. So it's probably not happening.
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