Barclay: Computer, begin new program. Create as follows: workstation chair. Now, create a standard alphanumeric console, positioned for the left hand. Now an iconic display console, positioned for the right hand. Tie both consoles into the Enterprise main computer core, utilizing neural-scan interface.
Enterprise Computer: There is no such device on file.
Barclay: No problem. Here's how you build it.
Both of Julian's parents were Christians, and he was a student of the Bible. He essentially rejected Christianity; that is the definition of "apostate". So the term is appropriate. If he had been a secular ruler, rather than politically targeting Christians in an effort to to reverse the religious course of the empire, it might not have been such a sticking point. A just ruler, perhaps-- but apostate.
Christianity was not the only, nor the dominant, religion of the Persian empire. And all but one historian believed that he was killed in battle, not assassinated by a Christian (or Christians). That one historian could be right, but it doesn't justify your confident position. I suspect your grasp on history is colored by your own religious beliefs.
Have you ever had issues with dust in your house?
How about humidity?
Small animals?
There is 0 chance you'll be successful against these issues. Might as well not have a computer!
We don't know how his crawlspace is designed. If it's designed within the building envelope, with a lined and insulated slab, insulated foundation walls, no vents, and kept at a temperature above the dewpoint, it's just a very short room. If not, then he will have challenges.
The hardest part of climbing the ladder of success is getting through the crowd at the bottom.