non-fractional shares will never be a part of pies because it prevents the key feature of fund balancing from functioning properly. All shares will be fractional in the end so there is no point to try and add non-fractionals to the feature.
I agree, when using Pies I have far too many individual investments to easily track non-fractional shares just through the Investments tab.
It would be far easier to manage if i could add them directly to a pie and have them rounded up to the nearest whole share, or if there were some way to pin them to the pie menu.
Simply being able to sort investments by value would also solve this problem.