All of these different than Victron options still suffer the same dimensional issues facing the OP, unless his space is so close to the edge that a half inch or so in any direction makes a difference.
I've owned inverter/chargers from Trace, Outback, Magnum, Mastervolt, and Victron (currently have Victron). Of these, Mastervolt is the only one I would never buy again. Its configurability is abysmal, and it is designed to be tied into an entire Mastervolt ecosystem with few options to use well as a standalone.
Victron is almost the same in terms of tying one into a Victron ecosystem, although they do have better abilities to program them through a computer and USB-serial interface. However, this programming is in Sanskrit and can be very confusing for someone not versed in "Victron". Victron actually requires them to be "professionally" installed, although few hire one. There is no direct support from Victron - you must go through the dealer you bought it from if you have any questions or issues. If you buy from Amazon or similar on-line places, you are on your own from the start. Of three Victron units I've owned, one came DOA, and one began to fail after a year. Victron's popularity in the recreational boat market right now is about their ecosystem as it applies to lithium batteries. This market has become infatuated with complicated centralized engineering science projects around batteries, and Victron feeds into that with a lot of expensive gear that is not always best in class but necessary for the system. Once there, you are locked in for good.
Having said the above, I'd buy another Victron Multiplus if the current one needs replacement. The reason is that it does a few things I like, and it exactly fits the space I have to mount it. I wouldn't say it performs any better or worse than the others I've owned. The Multiplus, a control panel for it, and a battery monitor are the only Victron gear we have, so locking into an ecosystem is of no concern to me.
Of the above interter/chargers I've experience with, Trace and Outback were my favorites in terms of performance, configurability, and ease of use. Magnum was close behind. Trace has been folded into Xantrex, and Outback might not be making the mobile units anymore.
Mark