I agree with the original poster, and I had the same issue a year ago in prep season 2021, with the 2020 tax year being my first using ProConnect (and not happy about it).  

It is now tax season 2022 (preparing 2021 tax returns) and I'm appalled that the ProConnect Tax Planner makes us start with 2020 as the base year.  Seriously?????  What kind of sense does that make?  I need to project a 2022 tax plan for a client with a complicated tax situation, and I need to start with his 2021 data (which has been reviewed and finalized).   This only makes sense, but 2021 data is not a base year option, and in order to have a projection with a column for 2022, I have to choose the 3-year projection - with Column 1 being 2020 - which my client does not care about.  And all three columns start out with 2020 data so now I have to input all of my 2021 amounts and then my 2022 amounts, and his situation is not simple.

It gets worse: Intuit says on its main Tax Planner web page that rental income can't be adjusted.  Rental income input isn't even an option on the side bar, although Business and Farm both are - as are PAL Limitations, except that you can't change anything on that page. 

My client sold his rental property early in 2021.  But the 2020 loss is carrying over to 2021 - which I can't change to the correct much smaller 2021 loss, then it's disallowing it due to high income (gain on the sale of that property).  So the planner has carried over that loss to 2022 and added it to the original 2020 loss, even though 2022 rental income should be nonexistant - but I can't change any of this.   All I can do is create hokey entries on the "Other Income" worksheet to force the correct amount of total income.

The main purpose of the Planner is to have a worksheet to review with the client (as opposed to the 1040-ES worksheet, which a normal taxpayer would not be able to follow) but I have to explain the existence of false and contradictory entries and point out that he can ignore the first column for 2020.

It still gets worse.  There's no FTC in the planner, so the client's large 2021 tax is not being offset by the large tax credit he is receiving on the sale of his foreign property. 

The program has entered the 2020 1099-R withholding in all three years, but there's no place to change the amount.  I'll have to fake it by adding the significant 2022 increase (due to a new RMD) to wage withholding. 

It is taking a 2022 standard deduction of $14,850 for a single individual over age 65 - the correct amount is $14,700.

And finally, for 2022 only, the Planner has incongruously given my client a $500 "Child Tax Credit & Other Dependent Credit" that I can't trace to anything - certainly not to any input that I made, or that this client has ever been entitled to.  This just appears out of thin air.  He only has retirement and investment income.

The Planner is basically useless, and certainly is not good enough for a client to see.

I've been spoiled by years of using ProSeries, which was a professional product.  ProConnect is not a professional product.  Unfortunately, having only a few remaining clients that I want to help out before we all fully retire, the cost of ProSeries is not supportable, and ProConnect was the only viable option.  I don't recommend it to anyone who is building a professional practice.