I'm new to Step Up Transformers

There is no better or worse here. It’s what works out in your system. I’ve heard inexpensive amps outperform expensive amps in a particular setup. So using the MC section of a very good phonostage doesn’t mean it will sound better or worse than using the MM with a SUT. If someone has great synergy with the built in MC then they are fortunate. But if the built in MC isn’t a good sonic balance with the cartridge, a person has a ton of flexibility using the MM section and exploring the many SUT’s available.  In my experience, it works out exceptionally well in getting the correct balance, - detail, dynamics, fullness, transparency, naturalness, etc. 

Keep in mind that what you’re proposing, assembling essentially a collection of SUTs so one can experiment with mating to one or several LOMC cartridges in pursuit of a best match, can easily become very expensive, time consuming, and possibly so troublesome as to discourage one from pursuing the hobby at all. Perhaps it works for you, but it’s not tenable for everyone who otherwise wants to use vinyl as a source.

It sure is an expensive pursuit.  My Consolidated Silver cost $5,500, my Bob's Devices was $1,200.  I believe the Ortofon is now around $1,800.  To these prices you need to add interconnects.  It is a lot easier, cheaper and cleaner to just buy a good high gain phono stage.  My PS Audio Stellar has that capability which is why I bought it.  In fact it is what I am listening to today in my new system.  It makes more sense to join a club if possible that accommodates member loans/exchanges or at least get togethers to try different SUTs or what not. 

It sure is an expensive pursuit

@billstevenson you ain't kidding.  I have a VDH current phono stage, and a Corralstone cart.  I'd have to get a quality voltage phono and a quality SUT.  It'll be a long while - dealing with other rabbit holes

Lewn, if just because it may not work for you doesn’t mean it doesn’t work for someone else. They’re  are tons of audiophiles that have a huge inventory of cables, tubes, cartridges as so on with many tweaks. That is because they buy this extra stuff in pursuit of the best sound they can get.