Focal Maestro Utopia , need advice for AMP/PRE

I can only dream of owning speakers such as those Focals. But to answer your question, the Pass amp should easily drive them. Focal Maestro Utopia has high sensitivity and your X350.5 puts out 700 wpc into 4 ohms. The Focals are rated at 4 ohms, but can drop as low as 2 ohms and IMO the high current of the Pass amp would not have a problem.

I see that owners report a long burn-in period for the Focals, so give them some break-in time before you judge them.
And unless you make some changes to your room acoustics, you will never get the most out of your system. There were many suggestions in your other thread.

"However, it demands to be used with amplifiers unfazed by its wicked load impedance in the upper bass."

...From the review: your Pass qualifies.
Don't be influenced by your dealer that you need a new amp.

"Czbbcl...
I would listen to the speakers prior to any amp replacement and then if you feel it is necessary you may want to look at the Pass X600.5's"

Not a bad idea; move up to the Pass X600.5 Monoblocks.
https://passlabs.com/products/amplifiers/x.5/x600.5

You've been getting good advice on amps so far, but you'll never know the true sound of your system until you break-in the speakers.