I agree not using ARC and streaming from the TV is best practice. Most optical cables will only do ARC up to ~10m (33ft). Most optical cables are actually hybrid cables that have optical for video but a thin copper wire that runs along them for ARC/e-ARC. This is true for Bullet Train and Ethereal. Cleerline specs state their cables will do ARC up to 20 meters. All 3 companies are very good choices for cables and companies that actually know their stuff, but ARC is a limitation with many optical cables.

I wouldn't worry about the cable frying the HDMI board of the receiver or TV, but I do worry about any type of active/optical cable dying over time or with a surge. The chips inside these cables are not very robust at their size and a surge can take them out. Some also run hot and that decreases the lifespan of circuitry. So, make sure it is easy to change the cable later in case of problems.

At 50 feet you have some possible solutions.

is the Cleerline optical cable mentioned above.

If you only need 4K you can use a passive HDMI cable and an Ethereal GA1 or GA2.

If you only need ARC/e-ARC you can use AVPro Edge EARC extender and run Cat6 cable.

If you have sources going through the receiver and need ARC/e-ARC you can also run Cat 6 cable with an HDMI extender. Just make sure the extender can do ARC. The disadvantage of an extender is it does compress the video signal. So, you lose some picture quality. The better extenders it would be difficult to notice any of the loss from compression.