The whole Snoke/Palpatine connection could really be more interesting.

For example, we could have Snoke be inhabited by the spirit of Palps, created specifically as a sacrificial vessel for Kylo to destroy. Under the TROS rules, if Kylo were to kill Snoke/Palps in anger, the Sith would possess Kylo and Palps would win. Snoke’s desire to turn Kylo fully dark is a necessary component of this plan. Since Snoke is killed by Kylo before he is dark, the spirit of Palps must return to Exegol and his ruined body once more, but through the Snoke plan he learns firsthand of Rey’s power.

To make this idea explicit in TFA/TLJ would go a long way to making the trilogy feel connected by a central villainous plan - the plan of Palpatine attempting to gain immortality first through the Skywalker line, then through that of his own granddaughter. It probably wouldn’t even be that hard. Snoke has a lot of mannerisms that mimic Palpatine already, so all that would be needed would be some explicit lines or words from Palpatine layered under Snoke’s lines like Gandalf/Sauruman from the Two Towers, and a burst of blue spirit energy when Snoke dies. TROS wouldn’t necessarily need to be changed in this regard, though it would be neat to have some confirmation that Snoke was Palps all along.