what TT has not made clear is will 2019 be installable on earlier versions of windows just don't ask for support or totally incompatible with earlier versions of windows. maybe if H&R block software supports win7, I'll move over to it. It's cheaper but I found more complicated to use.
i have tried converting. using free software. my win 7 MBR disk to GPT (Win 10 only installs on GPT with an exception when installing on virtual machine) . unfortunately, the free stuff only converts data disks ( those containing no OS) from MBR to GPT. there is software available for a fee that says it can convert OS disks from MBR to GPT but haven't tried it. I would then install 10 in dual boot mode. the problem with dual boot - not only do you have to install 10 but drivers for video cards, certain keyboards, mice and printers and other soft
2nd option install virtual machine and then install 10 in virtual mode. it will work win 7 MBR disk but with certain VM's you have the same issue with drivers. Supposedly, MS VM is a type 1 VM which can access the drivers on the win 7 partition.
3rd I have spare disks and sata ports so I can install 10 as a separate OS. there would still be need to install drivers and other software and the boot priority would have to be changed back and forth.
4th I work for a CPA firm which allows its people to prepare their returns for free - no e file. and there is no import from brokerage firms or transfer of data from TT.