The answer you link to is mine and is duplicated below.

You quote it ('below' refers to copy of answer) as:

In answers such as this one (below) I've seen suggestions that TVS diodes are not "reliable" under repetitive or continuous operation, such as a Zener diode might be used.

There's not such suggestion in the answer. I've highlighted the areas for you to examine in bold.

So the basis for your question "Can anyone provide more information to support or disprove this notion?" appears to be false.

The referred-to answer was address this question:

Is there a down side to using bidirectional TVS diodes in 12 V DC applications, such as across the coil of the relay or solenoid, or to protect other sensitive equipment?

ANSWER GIVEN:

Usually the reason why not is reliability.

As its name suggests, a Transient Voltage Suppressor (TVS) is designed for suppressing the effects of infrequent and unusual transients into a board connector or cable. It's connected directly across that input, to dissipate ESD, lightning strikes etc.

It's not designed for dissipation of normal operating power in a circuit. Its body package typically cannot conduct power well compared to other components because it doesn't need to. It's datasheets reflect this, with discharges through it rated at a very low pulse width and repetition rate indeed to keep the peak power and average power dissipation right down.

So using a TVS outside of its rated behaviour will decrease its reliability and it will fail more quickly and unpredictably than its specified life.

A TVS is just an electronic component, like any other. And like any component, it has:

• characteristics that define its behaviour
• specifications that define its performance and reliability

The manufacturer will list only some of its characteristics as specifications, in datasheets and reliability data etc. The manufacturer will qualify the part's behaviour and reliability against those specs and guarantee against them.

Other characteristics aren't specified. And if you go outside the specs, and rely on unspecified component characteristics, you're on your own in uncharted territory with a good chance of sinking. For one or a few circuits, you may choose to take your chances and it may work out OK. But it may not and for many/most mass production situations, that's unacceptable because the cost of failures in the field swamps the cost of properly spec'd parts.

So, with a TVS as an operating current clamp, there simply are better alternative components and circuits to use that do give specified reliability.

And, as said above, usually lower business costs in the long and short term.

The [answer] you link to is mine and is duplicated below.

You quote it ('below' refers to the copy of [answer]) as:

In answers such as this one (below) I've seen suggestions that TVS diodes are not "reliable" under repetitive or continuous operation, such as a Zener diode might be used.

There's no such suggestion in the [answer]. 

I've highlighted the areas for you to examine in bold.

So the basis for your question "Can anyone provide more information to support or disprove this notion?" in [answer] appears to be false.

The referred-to [answer] was address this question:

Is there a down side to using bidirectional TVS diodes in 12 V DC applications, such as across the coil of the relay or solenoid, or to protect other sensitive equipment?

[ANSWER] GIVEN:

Usually the reason why not is reliability.

As its name suggests, a Transient Voltage Suppressor (TVS) is designed for suppressing the effects of infrequent and unusual transients into a board connector or cable. It's connected directly across that input, to dissipate ESD, lightning strikes etc.

It's not designed for dissipation of normal operating power in a circuit. Its body package typically cannot conduct power well compared to other components because it doesn't need to. It's datasheets reflect this, with discharges through it rated at a very low pulse width and repetition rate indeed to keep the peak power and average power dissipation right down.

So using a TVS outside of its rated behaviour will decrease its reliability and it will fail more quickly and unpredictably than its specified life.

A TVS is just an electronic component, like any other. And like any component, it has:

• characteristics that define its behaviour
• specifications that define its performance and reliability

The manufacturer will list only some of its characteristics as specifications, in datasheets and reliability data etc. The manufacturer will qualify the part's behaviour and reliability against those specs and guarantee against them.

Other characteristics aren't specified. And if you go outside the specs, and rely on unspecified component characteristics, you're on your own in uncharted territory with a good chance of sinking. For one or a few circuits, you may choose to take your chances and it may work out OK. But it may not and for many/most mass production situations, that's unacceptable because the cost of failures in the field swamps the cost of properly spec'd parts.

So, with a TVS as an operating current clamp, there simply are better alternative components and circuits to use that do give specified reliability.

And, as said above, usually lower business costs in the long and short term.