Suggestion: change the way XM appears and the amount of XM each dot represents
The rainbow XM currently on the ground raises an interesting idea. What if XM looked different all the time and different colours represented a different amount of XM per dot? Two options would be level and rarity.
Level-based XM could be like resonators and bursters. Level 1 will get you 20XM per dot up to level 8 giving you 160XM per dot.
Rarity-based XM could be like mods. Common could be 50XM per dot, rare could be 100XM per dot and very rare could be 200 XM per dot.
You could then increase the level/rarity of XM around special events, e.g. IFS and anomalies.