Yes, that's a good thing. 20 in, 20 out. You're 900VA should have a 7.5A fuse protecting it from overload.
Always recommended at least double the capacity on the iso as the maximum draw. Haven't I said that before? Particularly for class AB amps.
Now then... code (as mentioned by Jea48 in your previous thread)... That's tricky with DIY setups where the transformer is wired in any way not implicitly intended. It's been done hundreds, maybe thousands, of times but it's different from UL approved commercial products. If the local authority follows NEC to the letter, "balanced AC" is not allowed in residential applications. Minimum compliance would be GFCI outlets (preferably orange) and labeled "Warning Technical Power". I might also suggest "Not for lighting". There is also a perceptual leap between plug-ins and hard-wired because the nearby dedicated transformer or enclosure is a warning in itself. Lak's setup is fine because it's not balanced. Personally, I think it can be done responsibly but I'm not "the authority having jurisdiction".
Canadian CSA code agrees with 99% of all UL certifications but there is no provision for "balanced AC" Not exactly a loophole since it's pretty specific about single-phase wiring.
IOW: You're on your own there, bud. Risk/cost/reward... your decision.
In my business, I see boilers all the time that aren't strictly code compliant for their BTU's (million+) but that's fine, as long as they're approved and certified. Install incorrectly or make one little change and guess who's ash is on the line.
To those reading this and questioning balanced AC from a standard isolation transformer, notice the 240/120 specification.