If the engine has to come out anyway, I vote for removing them as a unit. Much easier than having to undo all those nuts & bolts that hold the two together, with one end in the car (under the dash) and the other end in the engine compartment.
The stand is by no means a necessity, IMO; if you have a suitable table. I've mostly used a table ... first time I used a (borrowed) stand, it convinced me to buy my own. As it happens, I've not done a full engine rebuild since buying it (just "make-do" quickies with the engine still in the car).
Even a "Grade 1" 5/16" bolt has a tensile strength of over 3000 pounds. 4 of them is overkill.