As the OP observes, Micah waits for Elohim, but it is El who is praised for pardoning transgression. Reflecting on the shift from Elohim to El, it seems to me that the question posed in Micah 7:18 is not rhetorical but one that holds the key to the answer.
The majority of English translations render el (Strong’s Hebrew 410) in Micah 7:18 as “God” with an uppercase g.
Who is a God like you, who pardons sin and forgives the transgression
of the remnant of his inheritance? – Mic 7:18 NIV
For comparison, the majority of translations render el in Ex 15:11 as “god” with the lowercase g:
Who among the gods is like you, LORD? – Ex 15:11
Based on the premise that El in Micah 7:18 is a title of God with a capital G and not just a noun referring to deity in general, I examine the rest of the verse with particular attention to the words nasa (Strong’s 5375) and nachalah (Strong’s 5159). Each word has more than one possible meaning. The word nasa is rendered as pardon in the NIV translation but could also mean to bear or carry. The word nachalah, rendered as inheritance, could also mean property or possession.
The different meanings of nasa and nachalah lead me to consider alternative interpretations of Micah 7:18. At first glance, El refers to He who forgives the transgression of the remnant, those that are of his possession (cf Is 43:1). But El could also refer to He who bears the transgression (cf Is 53) of the self-same remnant, those that are of his inheritance (cf Ps 2:7-8).
The two facets of El are thus reflected by and united in the same words, the first as primary and the second as though a mirror image. This duality of meaning implies a plurality of saving actions, but the construction of the text and the use of the singular El, instead of the plural Elohim, does not allow for a corresponding plurality of Gods. However, it removes any question that it is El who is doing both actions.