I agree with Daniel and Jake. - don’t split your cases unless you have a shitfucked crank and/or bearings.
Just clean & rebuild your trans, inspecting every part for weird play and / or ware and installing new pucks.
If you are putting a performance top end; you’ll want to flip second while you are in there and grind the cases to fit a larger front sprocket to keep rpms down.
I wouldn’t do the seals unless you have a leak; but it’s easy enough either way.
I’d swap the oil inject block off plate with one from treats and inspect it / how they removed the oil injector shaft.
As Jake mentioned; we won’t do full mail in za50 rebuilds At DMW any more; and I no longer have the time / staff to fully tune bikes with performance work done - BUT I actually will do all of the stuff that I mentioned above short of the full rebuild as a mail in service if you still want to pay to have it done.
If so, send our FB page a message or fill out the contact for on our website.
Thanks. Talk to you soon and/or good luck with the build!